Resonant leaky-mode optical devices and associated methods

• US 7,689,086 B2
• Filed: 07/25/2005
• Issued: 03/30/2010
• Est. Priority Date: 07/30/2004
• Status: Active Grant

• Current Assignee: University of Connecticut (State of Connecticut)
• Original Assignee: University of Connecticut (State of Connecticut)
• Inventors: Magnusson, Robert, Ding, Yiwu
• Primary Examiner(s): Wood; Kevin S
• Application Number:
  US11/188,452
• Publication Number:
  US 20060024013A1
• Time in Patent Office: 1,709 Days
• Field of Search: 385 8- 10, 385129-132, 385/149
• US Class Current: 385/129
• CPC Class Codes: G02B 6/124 Geodesic lenses or integrated gratings
• CPC Class Codes: H01S 5/0654 Single longitudinal mode emission
• CPC Class Codes: H01S 5/11 Comprising a photonic bandgap structure
• CPC Class Codes: H01S 5/18355 having a defined polarisation
• CPC Class Codes: H01S 5/187 using Bragg reflection
• CPC Class Codes: H01S 5/2027 Reflecting region or layer, parallel to the active layer, e.g. to modify propagation of the mode in the laser or to influence transverse modes
• CPC Class Codes: H01S 5/423 having a vertical cavity

Abstract

Optical devices with versatile spectral attributes are provided that are implemented with one or more modulated and homogeneous layers to realize leaky-mode resonance operation and corresponding versatile spectral-band design. The first and/or higher multiple evanescent diffraction orders are applied to excite one or more leaky modes. The one- or two-dimensional periodic structure, fashioned by proper distribution of materials within each period, can have a resulting symmetric or asymmetric profile to permit a broadened variety of resonant leaky-mode devices to be realized. Thus, the attributes of the optical device permit, among other things, adjacent, distinct resonance frequencies or wavelengths to be produced, convenient shaping of the reflection and transmission spectra for such optical device to be accomplished, and the wavelength resonance locations to be precisely controlled so as to affect the extent to which the leaky modes interact with each other. Further, the profile asymmetry allows for the precise spectral spacing at interactive leaky modes so as to provide greater flexibility in optical device design.

Claims

1. An optical resonant leaky-mode device comprising:

at least one substrate layer;

at least one spatially modulated, periodic waveguiding layer deposited over said substrate layer; and

at least one cover layer over said spatially modulated waveguiding layer,

wherein the period of said modulated waveguiding layer has an asymmetric structural profile, and

wherein parameters associated with the optical resonant leaky-mode device are defined to admit resonant leaky modes.

2. The optical resonant leaky-mode device of claim 1, wherein said spatially modulated waveguiding layer has one-dimensional periodicity.

3. The optical resonant leaky-mode device of claim 1, wherein said spatially modulated waveguiding layer has two-dimensional periodicity.

4. The optical resonant leaky-mode device of claim 3, wherein said two-dimensional periodicity is provided by any of a lattice dot pattern, a mesas pattern, or a hole pattern with an offset sublattice to create asymmetry, or any combination thereof.

5. The optical resonant leaky-mode device of claim 1, wherein the refractive index of said spatially modulated waveguiding layer is higher than the refractive indices of said substrate and said cover layer.

6. The optical resonant leaky-mode device of claim 1, wherein two or more spatially modulated waveguiding layers are deposited on said substrate.

7. The optical resonant leaky-mode device of claim 1, wherein said device is selected from the group consisting of a narrowband reflecting structure, a narrowband reflecting filter, a wideband reflecting structure, a wideband reflecting filter, a narrowband transmitting structure, a narrowband transmitting filter, a wideband transmitting structure, and a wideband transmitting filter.

8. The optical resonant leaky-mode device of claim 1, wherein said spatially modulated waveguiding layer has one-dimensional periodicity that is effective to impart polarization independence.

9. The optical resonant leaky-mode device of claim 1, wherein said spatially modulated waveguiding layer has one-dimensional periodicity, where the phase between two orthogonal components is 180 degrees so as to affect half-wave polarization plate.

10. The optical resonant leaky-mode device of claim 1, wherein said spatially modulated waveguiding layer has one-dimensional periodicity, where the phase between two orthogonal components is 90 degrees so as to affect quarter-wave plate.

11. An optical resonant leaky-mode device comprising:

a substrate, and

at least one thin, periodically modulated waveguiding layer deposited on said substrate, said waveguiding layer possessing asymmetric grating profile for breaking the resonant leaky mode degeneracy at normal incidence,

wherein parameters associated with the optical resonant leaky-mode device are defined to admit one or more resonant leaky modes and to provide precise spectral spacing of interacting leaking modes.

12. The optical resonant leaky-mode device of claim 11, wherein said waveguiding layer has one-dimensional periodicity.

13. The optical resonant leaky-mode device of claim 11, wherein said waveguiding layer has two-dimensional periodicity.

14. The optical resonant leaky-mode device of claim 13, wherein said two-dimensional periodicity is provided by any of a lattice dot pattern, a mesas pattern, or a hole pattern with an offset sublattice to create asymmetry, or a combination thereof.

15. The optical resonant leaky-mode device of claim 11, wherein the refractive index of said waveguiding layer is higher than the refractive indices of said substrate and said cover.

16. The optical resonant leaky-mode device of claim 11, wherein two or more waveguiding layers are deposited on said substrate.

17. The optical resonant leaky-mode device of claim 11, wherein said device is selected from the group consisting of a narrowband reflecting structure, a narrowband reflecting filter, a wideband reflecting structure, a wideband reflecting filter, a narrowband transmitting structure, a narrowband transmitting filter, a wideband transmitting structure, and a wideband transmitting filter.

18. An optical resonant leaky-mode structure comprising:

at least one substrate layer;

at least one periodic, spatially modulated waveguiding layer deposited over said substrate layer; and

at least one cover layer over said modulated waveguiding layer to define a resonant leaky-mode assembly,

wherein parameters associated with the structure are defined to admit resonant leaky modes and wherein the period of said at least one periodic, spatially modulated waveguiding layer is defined by one or more materials distributed so as to define a profile that is selected from the group consisting of a symmetric profile, an asymmetric profile and combinations thereof.

19. The optical resonant leaky-mode structure of claim 18, wherein each profile is binary with one or more materials placed within each period.

20. The optical resonant leaky-mode structure of claim 18, wherein two or more materials are used to configure said profile.

21. The optical resonant leaky-mode structure of claim 18, wherein said profile has a saw-tooth shape.

22. The optical resonant leaky-mode structure of claim 18, wherein said structure is selected from the group consisting of an integrated/hybrid broadband VCSEL mirror, a transmission biosensor, a narrowband reflecting structure, a narrowband reflecting filter, a wideband reflector, a wideband reflecting filter, a narrowband transmitting structure, a narrowband transmitting filter, a wideband transmitting structure, and a wideband transmitting filter.

23. The optical resonant leaky-mode structure of claim 18, wherein said structure functions as a wideband reflector having a symmetric Type II profile.

24. The optical resonant leaky-mode structure of claim 18, wherein said structure is a polarizer with an asymmetric Type II profile.

25. The optical resonant leaky-mode structure of claim 18, wherein said structure is a polarizer with a symmetric Type II profile.

26. The optical resonant leaky-mode structure of claim 18, wherein said structure is an antireflection element with an asymmetric Type II profile.

27. The optical resonant leaky-mode structure of claim 18, wherein said structure is an antireflection element with a symmetric Type II profile.

28. The optical resonant leaky-mode structure of claim 18, wherein said material within each period is anisotropic, thereby providing TE-TM mode conversion within said waveguiding layer and permitting interaction between dissimilar modes.

29. The optical resonant leaky-mode structure of claim 18, wherein said at least one modulated waveguiding layer includes a periodic grating layer and a separate homogenous waveguide layer adjacent to said periodic grating layer.

30. The optical resonant leaky-mode structure of claim 18, wherein said at least one modulated waveguiding layer includes a combination of homogeneous layers and periodic grating layers.

31. The optical resonant leaky-mode structure of claim 18, wherein the at least one modulated waveguiding layer is characterized by a fill factor, and wherein said at least one modulated waveguiding layer is adapted to permit dynamic variation of said fill factor.

32. The optical resonant leaky-mode structure of claim 31, wherein said fill factor is dynamically varied in connection with at least one of the following:

(i) spectral tuning and (ii) spectral shaping.

33. The optical resonant leaky-mode structure of claim 31, wherein the fill factor is varied by insertion of a grating ridge into a grating groove.

34. The optical resonant leaky-mode structure of claim 33, wherein the grating ridge is inserted by at least one of mechanical or a micro-electromechanical technique.

35. The optical resonant leaky-mode structure of claim 33, wherein the grating ridge and the grating groove have substantially rectangular shapes.