Efficient light engine systems, components and methods of manufacture

• US 6,356,700 B1
• Filed: 06/08/1999
• Issued: 03/12/2002
• Est. Priority Date: 06/08/1998
• Status: Expired due to Fees

• Current Assignee: Karlheinz Strobl
• Original Assignee: Karlheinz Strobl
• Inventors: Strobl, Karlheinz
• Primary Examiner(s): Schuberg, Darren
• Assistant Examiner(s): BOUTSIKARIS, LEONIDAS
• Application Number:
  US09/328,256
• Time in Patent Office: 1,008 Days
• Field of Search: 362/297, 362/298, 362/300, 362/302, 362/346, 385/901, 385/31, 385/147, 359/859
• US Class Current: 385/147
• CPC Class Codes: G02B 6/0006 Coupling light into the fibre in general G02B6/4298
• CPC Class Codes: G02B 6/4298 coupling with non-coherent light sources and/or radiation detectors, e.g. lamps, incandescent bulbs, scintillation chambers
• CPC Class Codes: G03B 21/204 using secondary light emission, e.g. luminescence or fluorescence using different colours G03B33/00; if related to video signals H04N9/3197
• CPC Class Codes: G03B 21/208 Homogenising, shaping of the illumination light
• CPC Class Codes: Y10S 385/901 Illuminating or display apparatus

Abstract

An étendue efficient angle conversion system that operates in a quasi-imaging mode. This system is capable of generating angular and spatial axial asymmetric output beams and is also capable of incorporating therein optional color reformatting capabilities. With the aid of anamorphic beam transformers such asymmetric beams can further be reformatted to spatially and angularily match particular illumination needs of a target. This system can further be applied to the design of fiber optic illumination systems and projection display systems and can further be combined with delivery efficiency maximization concepts. In addition, delivery efficiency improvements of light engines can be obtained with the use of optimized lamp, reflector, integrators, anamorphic beam transformers, coupling optics, etc.

Claims

1. A light engine for efficient energy delivery and simultaneous é

tendue efficient area and angle reformatting of a gas discharge lamp comprising;

a retro reflector system;

a primary reflector system having a first and second focal point F₁ and F₂ defining a system axis; and

a gas discharge lamp system comprising a gas tight, semitransparent envelope enclosing an energizable gas and including means for creating and energizing at least one spatially extended, semitransparent region of said gas, thereby creating an emission source S that emits electromagnetic energy escaping from said lamp system through said envelope and with the longest dimension of said source S defining a source axis;

said source axis being aligned substantially perpendicular to said system axis;

said source S being located proximate to said focal point F₁ and said lamp system having a respective emission é

tendue function E_S(p) in at least one wavelength region of interest and with p representing the percentage of total emitted energy emitted by said lamp system in said wavelength region of interest;

said retro reflector system having an exit port and comprising at least one primary concave retro-reflector, said retro reflector system collecting and retro-reflecting a portion of said energy emitted from said source S back into said lamp system proximate to said source S, the combination of said source S and said retro reflector system thereby creating an effective retro-reflected emission source S_r, said source S_r having a respective spatial dependent emission intensity distribution SI(x,y;

S_r) in a plane perpendicular to said system axis and containing said source axis;

said primary reflector system comprising at least one concave reflector, said primary reflector system collecting and reflecting a portion of the energy emitted from said source S_r and concentrating the major portion of said reflected energy approximately symmetrically around said envelope near said focal point F₂, thus creating a secondary emission source S′

having a respective spatial dependent intensity distribution SI(x,y;

S′

) perpendicular to said system axis and proximate to focal point F₂; and

where curvatures, spectral reflectivities and transmissivities and extent of said primary reflector system and said retro reflector system and said exit port are chosen for efficient energy delivery in said at least one wavelength region of interest to said secondary source S′ and

such that said spatial asymmetric intensity distribution SI(x,y;

S′

) has its longest dimension substantially parallel to said source axis and is a quasi-imaging magnification of said intensity distributions SI(x,y;

S_r) and the beam exiting said retro reflector system through said exit port has a secondary source é

tendue function E<sub>S′

i</sub>(p) in said wavelength region of interest that is minimally increased over said source é

tendue function E_S(p) for at least one of said p-values;

thereby forming a minimal light engine (MLE).

2. The light engine as defined in claim 1, wherein said source S and aid secondary emission source S′

have a respective angular dependent emission energy density function AI(φ

,Ψ

;

S) and AI(φ

,Ψ

;

S′

) near said respective focal points F₁ and F₂ that is asymmetric in a plane containing said source axis and perpendicular to said system axis, thus generating both a spatially and angularly asymmetric, é

tendue efficiently reformatted output beam.

3. The light engine as defined in claim 1, wherein said lamp system comprises a lamp selected from the group consisting of an AC gas discharge arc lamp, a DC gas discharge arc lamp, a single envelope lamp, a double envelope lamp, an electrode-less, microwave powered, wall stabilized lamp, and wherein said gas is selected from the group consisting of Hg, Hg₂, Xe, Ar, Kr, metal halide salt vapors and molecules containing an element from the halogen group of the periodic table, and wherein said primary reflector system is selected from the group consisting of an elliptical and aspherical reflector, and wherein the components of said retro reflector system are selected from the group consisting of an spherical, toroidal, elliptical and a-spherical reflector, and wherein said quasi-imaging magnification of said primary reflector system has a value between 1.5 and 5.

4. The light engine as defined in claim 1, wherein said envelope has optical beam redirection properties and where aspherical deviations of said retro reflector system from a basic spherical form compensate for a portion of said optical beam redirection properties, and where said deviations reduce the spatial extent of said spatial dependent emission intensity distribution SI(x,y;

S′

).

5. The light engine as defined in claim 1, wherein said envelope has optical beam redirection properties and where non-axial symmetric deviations of said primary reflector system from a basic axial symmetric ellipsoidal form compensates for at least a portion of said optical beam redirection properties, and where said non-axial symmetric deviations reduce the spatial extent of said spatial dependent emission intensity distribution SI(x,y;

S′

).

6. The light engine as defined in claim 1, wherein said at least one oncave reflector comprises a primary reflector section and at least one auxiliary concave retro reflector section having a primary curvature radius R₁<

R₀ with R₀ representing the primary curvature radius of said primary concave retro reflector and wherein said primary concave retro reflector and said at least one auxiliary retro reflector section are located opposite to each other with respect to said lamp system and with said at least one auxiliary concave retro reflector section reflecting a portion of the energy collected from said source S back into said source S.

7. The MLE as defined in claim 1, wherein said retro reflector system comprises said primary concave retro reflector having a first exit opening and a primary curvature radius R₀ and at least one i-th auxiliary concave, retro reflector having at least one i-th second exit opening and a primary curvature radius R_2,i>

R₀, and wherein said primary and said at least one i-th auxiliary retro reflector are located opposite to said primary reflector system with respect to said lamp system, and wherein a portion of said energy emitted directly from said source S and exiting through said first exit opening is collected and retro-reflected back proximate to said source S by said at least one i-th auxiliary concave retro-reflector, and wherein a portion of the electromagnetic energy concentrated by said primary reflector system exits said MLE through said at least one i-th second exit opening and wherein said exit port comprises said first exit opening and said at least one i-th second exit opening.

8. The MLE as defined in claim 7, wherein the combination of said at least one auxiliary concave retro reflector section and of a least one reflector subsection of said retro reflector system form a conjugate, reflective ring-cavity with said source S being located substantially at the focus of said reflective ring-cavity.

9. A light engine as defined in claim 1, wherein the spectrum of the energy escaping said exit port has relative gains in at least one wavelength band caused by an electromagnetic energy-material interaction of retro-reflected electromagnetic energy by said retro reflector system with said gas enclosed by said envelope over the spectrum of said energy emitted by said lamp system alone.

10. The light engine as defined in claim 9, wherein at least one component of said gas enclosed in said envelope is selected in combination with said electromagnetic energy-material interaction to generate a more spectrally usable energy beam for a balanced red, green and blue color band generation for color image projection display applications.

11. The light engine as defined in claim 1, wherein said envelope has an antireflection coating.

12. The light engine as defined in claim 1, wherein said lamp system has lamp posts with seals near their respective ends and a center envelope section, where said seals are preferably being operated below a preselected temperature and said center envelope section is preferably being operated within a preselected temperature range that is substantially higher than said preselected temperature, and wherein said primary and said retro reflector systems form a cavity which provides sufficient thermal isolation between said center envelope section and said seals so that the temperature of said seals can be lowered below said preselected temperature and said center envelope section can be operated within said preselected temperature range.

13. The light engine as defined in claim 1, wherein said primary reflector system has a surface shape which is accepted to achieve a more spatially uniform intensity profile at a minimal é

tendue loss at an energy collection surface near said focal point F₂.

14. A light engine comprising:

a sealed optical system enclosing an energizable gas, and said sealed optical system comprising a primary reflector system, a retro reflector system and at least one i-th exit window;

means for energizing said gas between two opposite electrodes tips, said tips defining a source axis and energizing a semitransparent, spatially extended plasma region, thereby creating an emission source S having an asymmetric spatial dependent intensity distribution SI(x,y;

S) and an asymmetric angular dependent emission energy density function AI(φ

,Ψ

;

S) in a plane containing said source axis;

said primary reflector system having a first focal point F₁ and a least one secondary i-th focal point F_2,i defining an i-th system axis;

said source S being located proximate to said first focal point F₁ an d said source axis being aligned substantially perpendicular to said at least one i-th system axis;

said retro reflector system having at least one i-th exit port sealed by said at least one i-th exit window and comprising at least one concave retro reflector, said retro reflector system collecting and retro-reflecting a portion of said energy emitted from said source S back into said source S, the combination of said source S and said retro reflector system thereby creating an effective retro-reflected emission source S_r, and said source S_r having a respective spatial dependent emission energy density function emission intensity distribution SI(x,y;

S_r) in a plane perpendicular to said system axis and containing said source axis;

said primary reflector system comprising at least one concave reflector, said primary reflector system collecting and reflecting a portion of the energy emitted from said source S_r and concentrating a substantial portion of said collected electromagnetic energy around said electrodes and through said at least one i-th exit window near said at least one secondary focal point F_2,i, thus forming at least one i-th secondary emission source S′

_i, having its longest dimension oriented substantially parallel to said source axis and having a respective spatial dependent intensity distribution SI(x,y;

S′

_i) perpendicular to said i-th system axis and proximate to said at least one secondary focal point F_2,i; and

where curvatures, and extent of said primary and retro reflector systems and of said at least one i-th exit port are chosen to produce at least one secondary source S′

_i having an intensity distribution SI(x,y;

S′

_i) that is a quasi-imaging magnification of said intensity distribution SI(x,y;

S_r) and having an angular dependent AI(φ

,Ψ

;

S′

) with its biggest extent oriented approximately perpendicular to said source axis and its smallest extent approximately parallel to said source axis;

thereby forming a sealed minimal light engine without any envelope blockage losses.

15. The light engine as defined in claim 14, wherein said primary and said retro reflector systems and said window are made from group consisting of of quartz, sapphire, glass, metal and heat conducting ceramic material, and wherein the primary component of said energizable gas is Xe, and wherein said plasma emission region is localized by two respective opposed tungsten containing electrodes which have a gas tight electrically and thermally conductive seal through said reflector body, and wherein said primary reflector system comprises sections from an axial symmetric ellipsoid having said i-th system axis as axis of symmetry, and wherein said primary retro reflector system has said source axis as axis of symmetry and are selected from a group consisting of a spherical, toroidal, elliptical and aspherical toroidal reflector, and wherein said quasi-imaging magnification of said primary reflector system has a value between 1.5 and 5, and wherein said primary reflector system is selected from a group consisting of a single axis system and a dual axis system.

16. A light engine comprising:

a quasi-imaging minimal light engine (MLE) for collection of electromagnetic energy emitted from a gas discharge lamp having an electromagnetic energy emission source S and for concentration of a portion of said collected energy, thus forming a respective spatial and angular reformatted secondary source S′

;

a configurable illumination target comprising at least one configurable pixel generating at least one processed output beam;

a coupling optic collecting a portion of electromagnetic energy emitted by said secondary source S′ and

providing an illumination beam for said configurable illumination target; and

a projection optic collecting a portion of said at least one processed output beam from said configurable illumination target and further including means to translate said collected processed output beam portion into a scaled image of said configurable illumination target at a remote display target; and

with

said MLE comprising;

a retro reflector system;

a primary reflector system having a first and second focal point F₁ and F₂ defining a system axis; and

a gas discharge lamp system comprising a gas tight, semitransparent envelope enclosing an energizable gas and including means for creating and energizing at least one spatially extended, semitransparent region of said gas, thereby creating said emission source S that emits electromagnetic energy escaping from said lamp system through said envelope and with the longest dimension of said source S defining a source axis;

said source axis being aligned substantially perpendicular to said system axis and said source S being located proximate to said focal point F₁;

said retro reflector system having an exit port and comprising at least one primary concave retro-reflector, said retro reflector system collecting and retro-reflecting a portion of said energy emitted from said source S back into said lamp system proximate to said source S, the combination of said source S and said retro reflector system thereby creating an effective retro-reflected emission source S_r emitting into a substantially reduced solid angle space than said source S emits and said source S_r having a respective spatial dependent emission intensity distribution SI(x,y;

S_r) in a plane perpendicular to said system axis and containing said source axis;

said primary reflector system comprising at least one concave reflector, said primary reflector system collecting and reflecting a portion of the energy emitted from said source S_r and concentrating the major portion of said reflected energy approximately symmetrically around said envelope near said focal point F₂, thus creating said secondary emission source S′

having a respective spatial dependent intensity distribution SI(x,y;

S′

) perpendicular to said system axis and proximate to focal point F₂; and

where curvatures and extent of said primary reflector system and said retro reflector systems and said exit port are chosen such that said spatial asymmetric intensity distribution SI(x,y;

S′

) has its longest dimension substantially parallel to said source axis and is a quasi-imaging magnification of said intensity distributions SI(x,y;

S_r);

thereby forming a projection light engine (PLE).

17. The light engine as defined in claim 16, wherein said lamp system comprises a lamp selected from the group consisting of an AC gas discharge arc lamp, a DC gas discharge arc lamp, a single envelope lamp, a double envelope lamp, an electrode-less, microwave powered, wall stabilized lamp, and wherein said gas is selected from the group consisting of Hg, Hg₂, Xe, Ar, Kr, metal halide salt vapors and molecules containing an element from the halogen group of the periodic table, and wherein said primary reflector system is selected from the group consisting of elliptical and aspherical reflectors, and wherein the components of said retro reflector system are selected from the group consisting of spherical, toroidal, elliptical and aspherical reflectors, and wherein said quasi-imaging magnification of said primary reflector system has a value between 1.5 and 5, and wherein said configurable illumination target is selected from a group consisting of a reflective light valve, a transmissive light valve, a liquid crystal display device, a DMD, a TMA, a slide, a single frame of a film projector, a reflective image and a semitransparent image, and wherein, said coupling optic comprises optical elements selected from a group consisting of a symmetric beam transformer, an asymmetric beam transformer, a imaging area/angle transformers, a non imaging area/angle transformers, a non area reformatting light guide and an area reformatting light guides.

18. A light engine comprising:

a minimal light engine (MLE) for collection of electromagnetic energy emitted from a lamp having an electromagnetic energy emission source S and for concentration of a portion of said concentrated energy, thus forming a respective spatial and angular reformatted secondary source S′

; and

an anamorphic beam transformer (ABT)having at least one input port and at least one output port, said at least one input port collecting electromagnetic energy that has been emitted from said secondary source S′ and

transporting a portion of said collected energy to said at least one output port of said ABT;

said MLE comprising;

a retro reflector system;

a primary reflector system having a first and second focal point F₁ and F₂ defining a system axis; and

a lamp system including means for energizing at least one spatially extended emission source S that emits electromagnetic energy escaping from said lamp system in a non symmetric angular dependent manner and with the narrowest dimension of the angular dependent intensity distribution AI(φ

,Ψ

;

S) of said lamp system defining a source axis;

said source axis being aligned substantially perpendicular to said system axis and said source S being located proximate to said focal point F₁;

said retro reflector system having an exit port and comprising at least one primary concave retro-reflector, said retro reflector system collecting and retro-reflecting a portion of said energy emitted from said source S back into said lamp system proximate to said source S, the combination of said source S and said retro reflector system thereby creating an effective retro-reflected emission source Sr emitting into a substantially reduced solid angle space than said source S emits and said source S_r having a respective spatial dependent emission intensity distribution SI(x,y;

S_r) in a plane perpendicular to said system axis and containing said source axis;

said primary reflector system comprising at least one concave reflector, said primary reflector system collecting and reflecting a portion of the energy emitted from said source S_r and concentrating the major portion of said reflected energy approximately symmetrically around said source S near said focal point F₂, thus creating said secondary emission source S′

having a respective spatial dependent emission energy density function SI(x,y;

S′

) and an asymmetric angular dependent AI(φ

,Ψ

;

S′

) perpendicular to said system axis and proximate to said focal point F₂; and

where curvatures and extent of said primary reflector system and said retro reflector systems and said exit port are chosen such that said angular dependent asymmetric emission energy density function AI(φ

,Ψ

;

S′

) has its shortest dimension substantially parallel to said source axis and

where said spatial dependent intensity distribution SI(x,y;

S′

) is a quasi-imaging magnification of said intensity distributions SI(x,y;

S_r); and

where said MLE emits an asymmetric angular dependent output beam which has a wider angular spread orthogonal to said source axis and a narrower angular spread parallel to said source axis, and

wherein said ABT resizes said spatial dependent intensity distribution SI(φ

,Ψ

;

S′

) and said angular dependent emission energy density function AI(φ

,Ψ

S′

) in an asymmetric manner parallel and orthogonal to said source axis between said input and said output port thereby forming an anamorphic beam transformer light engine (ABTLE).

19. The light engine as defined in claim 18, wherein said lamp system comprises a lamp selected from the group consisting of an AC gas discharge arc lamp, a DC gas discharge arc lamp, a single envelope lamp, a double envelope lamp, an envelope-less electromagnetic emission source, an envelope less electromagnetic emission source with said primary reflector system and said and retro reflector system and said output port forming an effective envelope for said source S, an electrode-less, microwave powered, wall stabilized lamp, a filament lamp, a Tungsten-Halogen filament lamp, and a solid state emission source and wherein the envelope for said lamp systems having an envelope is filled with elements from the group consisting of vacuum, Hg, Hg₂, Xe, Ar, Kr, metal halide salt vapors and molecules containing an element from the halogen group of the periodic table, and wherein said primary reflector system is selected from the group consisting an elliptical and aspherical reflector, and wherein the components of said retro reflector system are selected from the group consisting of spherical, toroidal, elliptical and aspherical reflectors, and wherein said quasi-imaging magnification has a value of at least 1.5 and no more than 5, and wherein said ABT is selected from a group consisting of a hollow reflective tube, a hollow reflective tube with a reflective lid at its input port having a transparent section which is smaller than the input section of said reflective tube, a solid, total internal reflecting rod, a solid, total internal reflecting rod having a reflective coating at its input port that has a transparent section which is smaller than the input section of said rod, a liquid filled total internal reflective tube, a liquid filled total internal reflective tube with a reflective lid at its input port having a transparent section which is smaller than the input port of said liquid filled tube, a tapered single optical fiber, a fiber optic bundle with different cross sectional geometry at its respective input and output port, a light guide with different input and output cross sectional geometry, a 1-dimensional tapered light guide, a two-dimensional tapered-light guide, a—

two-dimensional tapered light guide with different horizontal and vertical taper angle, a two step light guide combining a first 1-dimensional tapered section with a continuing straight section having a constant cross sectional shape and area, a two step tapered light guide with a 2-dimensional tapered input section continuing on with a straight section with a constant cross sectional shape and area, a light guide with a curved input surface, a light guide with a curved output surface, a light guide with a flat output section polished at a not normal angle to the main light guide propagation axis, a hollow light guide assembled from at least one component, a light guide with an auxiliary optic between said input port of said light guide and said exit port of said MLE, and an anamorphic optical imaging system with different image magnification parallel and orthogonal to said source axis.

20. The light engine as defined in claim 18 wherein said at least one output port of said anamorphic beam transformer system illuminates an additional optical system having a given spatial and angular dependent acceptance function, and where said ABT substantially provides an energy delivery efficient, area and angle beam reformatting function between the spatially and angular asymmetric output beam of said MLE and said spatial and angular dependent acceptance function of said additional optical system.

21. A light engine comprising:

a minimal light engine (MLE) for collection of electromagnetic energy from a filament lamp having an emission filament source S and concentrating of a portion of said energy to form at least one respective spatial and angular reformatted i-th secondary source S′

_i; and

a light guide having at least one input and one output port, said light guide collecting electromagnetic energy emitted from said at least one i-th secondary emission source S′

_i with at least one input port and delivering a substantial portion of said collected energy to at least one output port; and

said MLE comprises;

a retro reflector system;

a primary reflector system having a first focal point F₁ and a least one secondary i-th focal point F_2,i defining an i-th system axis;

a filament lamp comprising a semitransparent envelope enclosing a tungsten filament and including means for heating said filament, thereby creating said emission source S having a geometrical source center C that emits electromagnetic energy escaping said filament lamps through said envelope and with the longest direction of said filament defining a source axis and the widest dimension orthogonal to said source axis defining a width W and a widest width axis;

said source axis being aligned perpendicular to said i-th system axis with the shortest distance D between said first focal point F₁ and said source center C fulfilling the equation D≧

2W;

said retro reflector system having at least one i-th exit port and comprising at least one concave retro reflector, said retro reflector system collecting and retro-reflecting a portion of said energy emitted from said source S back into said filament lamp and proximate to said source S, the combination of said source S and said retro reflector system thereby creating an effective retro-reflected emission source S_r, said source S_r having a respective spatial dependent emission intensity distribution SI(x,y;

S_r) in a plane perpendicular to said system axis and containing said source axis;

said primary reflector system comprising at least one concave reflector, said primary reflector system collecting and reflecting a portion of the energy emitted from said source S_r and concentrating a substantial portion of said collected electromagnetic energy approximately symmetrically around said envelope near said at least one secondary focal point F<sub>2′

i</sub>, thus creating at least one secondary emission source S′

_i, having a respective spatial dependent intensity distribution SI(x,y;

S′

_i) perpendicular to said i-th system axis and proximate to said i-th secondary focal point F_2,i; and

where curvatures and extent of said primary and retro reflector systems and said at least one i-th exit port are chosen to produce an at least one secondary source S′

_i having an intensity distribution SI(x,y;

S′

_i) along a respective minimal é

tendue surface that is a quasi-imaging magnification of said intensity distribution SI(x,y;

S) of said source S;

thereby forming a filament source light guide light engine.

22. The light engine as defined in claim 21, wherein the minimal é

tendue surface of said at least one secondary source S′

_i is curved and where said widest width axis is oriented orthogonal to said i-th system axis.

23. The light engine as defined in claim 21, wherein said light guide selected from a group consisting of an anamorphic beam transformer, an é

tendue efficiently matched anamorphic beam transformer, a symmetrical light guide, and area reformatting light guide, and area and angle reformatting light guide, and wherein said at least one input port of said light guide is selected from a group consisting of a flat input area, a curved input area, a perpendicular oriented input area, a tilted input area, a stepwise approximated curved input area and a combination of an auxiliary, local beam redirection optic combined with a smooth input area, and wherein said quasi-imaging magnification value of said primary reflector system is between 1.5 and 5.

24. The light engine as defined in claim 22, wherein the curvature of said primary reflector system is chosen to bend the curvature of said minimal é

tendue surface to a preselected curvature.

25. A light engine comprising:

a quasi-imaging minimal light engine (MLE) for collection of electromagnetic energy emitted from a fluorescing emission volume source S having a longest dimension forming a source axis and for concentration of a portion of said collected energy, thus forming a respective spatial and angular reformatted secondary source S′

;

means for exciting said source S to emit electromagnetic energy in at least one first wavelength band by illuminating it with electromagnetic energy of at least one second wavelength band which is shorter in wavelength than said first band;

said MLE comprising;

a retro-reflector system;

a primary reflector system having a first and second focal point F1and F2defining a system axis; and

where said source axis being aligned substantially perpendicular to said system axis and said source S being located proximate to said focal point F1;

said retro-reflector system having an exit port and comprising at least one primary concave retro-reflector, said retro-reflector system collecting and retro-reflecting a portion of said energy emitted from said source S back proximal said focal point F1, the combination of said source S and said retro-reflector system thereby creating an effective retro-reflected emission source Sr emitting into a substantially reduced solid angle space than said source S emits and said source Sr having a respective spatial dependent emission intensity distribution SI (x,y;

Sr) in a plane perpendicular to said system axis and containing said source axis;

said primary reflector system comprising at least one concave reflector, said primary reflector system collecting and reflecting a portion of the energy emitted from said source Sr and concentrating the major portion of said reflected energy approximately symmetrically around said source S near said focal point F2, thus creating said secondary emission source S′

having a respective spatial dependent intensity distribution SI(x,y;

S′

) perpendicular to said system axis and proximate to focal point F2; and

where curvatures and extent of said primary reflector system and said retro-reflector systems and said exit port are chosen such that said intensity distribution SI (x,y;

S′

) is a quasi-imaging magnification of said intensity distributions SI(x,y;

Sr) and having an angular dependent emission energy density function AI(φ

,Ψ

;

S′

) with its biggest extent oriented approximately perpendicular to said source axis and its smallest extent approximately parallel to said source axis;

thereby forming a fluorescence conversion light engine.