Beam splitter for producing a plurality of splitted light beams for each of wavelength components of an incident light beam

• US 5,071,225 A
• Filed: 12/28/1990
• Issued: 12/10/1991
• Est. Priority Date: 12/29/1989
• Status: Expired due to Fees

• Current Assignee: Hoya Corporation, Dainippon Screen Manufacturing Company Limited (SCREEN Holdings Co., Ltd.)
• Original Assignee: Hoya Corporation, Dainippon Screen Manufacturing Company Limited (SCREEN Holdings Co., Ltd.)
• Inventors: Inoue, Teiji
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US07/635,767
• Time in Patent Office: 347 Days
• Field of Search: 350/171, 350/169, 350/166, 350/173
• US Class Current: 359/634
• CPC Class Codes: G02B 27/1006 for splitting or combining different wavelengths G02B27/1086, G02B27/141 take precedence
• CPC Class Codes: G02B 27/106 for splitting or combining a plurality of identical beams or images, e.g. image replication
• CPC Class Codes: G02B 27/142 Coating structures, e.g. thin films multilayers
• CPC Class Codes: G02B 27/144 using partially transparent surfaces without spectral selectivity G02B27/147 takes precedence
• CPC Class Codes: G02B 27/145 having sequential partially reflecting surfaces

Abstract

In a beam splitter for producing splitted light beams for each of first and second wavelength components of an incident light beam, first and second transparent blocks have first outgoing and second incident planar surfaces, respectively, which are bonded by an intermediate transparent layer with a band-pass layer and first and second subsidiary reflection layers interposed between the intermediate layer and the second incident planar surface and with the surfaces kept in parallel. Antireflection and primary reflection layers are formed on a first incident planar surface of the first transparent block that is parallel to the first outgoing surface. First and second semitransparent layers are formed on a second outgoing planar surface of the second transparent block that is parallel to the second incident planar surface. The incident light beam is directed from the antireflection layer towards the band-pass layer. The band-pass layer passes, towards the first semitransparent layer, a first outgoing light beam having the first wavelength component and reflects, towards the primary reflection layer, a second outgoing light beam having the second wavelength component to make the primary reflection layer reflect the second outgoing light beam towards the second semitransparent layer through the intermediate layer between the subsidiary reflection layers. In cooperation with the first and the second subsidiary reflection layers, the first and the second semitransparent layers produce the splitted light beams for the first and the second wavelength components, respectively.

Claims

1. A beam splitter supplied with a single incident light beam having first and second wavelength components for splitting said incident light beam into first and second outgoing light beams having said first and said second wavelength components, respectively, and for splitting each of said first and said second outgoing light beams into a plurality of partial light beams, said beam splitter comprising:

a first transparent block having first incident and first outgoing planar surfaces substantially parallel to each other, said first incident planar surface having a primary incident area and a primary reflection area, said primary incident area being for receiving said incident light beam to direct said incident light beam towards said first outgoing planar surface;

a primary reflection layer formed on said primary reflection area;

a second transparent block having second incident and second outgoing planar surfaces substantially parallel to each other, said second incident planar surface having a subsidiary incident area, first and second subsidiary reflection areas, and a remaining area, said second outgoing planar surface having first and second exit areas;

an intermediate transparent layer interposed between said first outgoing and said second incident planar surfaces;

a band-pass layer interposed between said intermediate transparent layer and said second incident planar surface and formed on said subsidiary incident area with said first outgoing and said second incident planar surfaces kept in substantially parallel to each other and with said incident light beam directed towards said subsidiary incident area through said intermediate transparent layer, said band-pass layer supplied with said incident light beam for passing said first outgoing light beam towards said first exit area and for reflecting said second outgoing light beam towards said primary reflection layer to make said primary reflection layer reflect said second outgoing light beam towards said second exit area through said remaining area;

first and second subsidiary reflection layers interposed between said intermediate transparent layer and said second incident planar surface and formed on said first and said second subsidiary reflection areas, respectively, with said first outgoing and said second incident planar surfaces kept in substantially parallel to each other; and

first and second semitransparent layers formed on said first and said second exit areas and supplied with said first and said second outgoing light beams for partially passing said first and said second outgoing +light beams, respectively, and for partially reflecting said first and said second outgoing light beams towards said first and said second subsidiary reflection layers to make said first and said second subsidiary reflection layers reflect said first and said second outgoing light beams towards said first and said second semitransparent layers, respectively, each of said first and said second semitransparent layers thereby producing said plurality of the partial light beams for each of said first and said second outgoing light beams.

2. A beam splitter as claimed in claim 1, wherein said first and said second transparent blocks and said intermediate transparent layer have refractive indexes which are substantially equal to one another.

3. A beam splitter supplied with a single incident light beam having first, second, and other wavelength components for splitting said incident light beam into first and second outgoing light beams having said first and said second wavelength components, respectively, and for splitting each of said first and said second outgoing light beams into a plurality of partial light beams, said beam splitter comprising:

a first transparent block having first incident and first outgoing planar surfaces substantially parallel to each other, said first incident planar surface having a primary incident area and a primary reflection area, said primary incident area being for receiving said incident light beam to direct said incident light beam towards said first outgoing planar surface;

a primary reflection layer formed on said primary reflection area;

a second transparent block having second incident and second outgoing planar surfaces substantially parallel to each other, said second incident planar surface having first and second subsidiary incident areas and first and second subsidiary reflection areas, said second outgoing planar surface having first and second exit areas;

an intermediate transparent layer interposed between said first outgoing and said second incident planar surfaces;

a first band-pass layer interposed between said intermediate transparent layer and said second incident planar surface and formed on said first subsidiary incident area with said first outgoing and said second incident planar surfaces kept in substantially parallel to each other and with said incident light beam directed towards said first subsidiary incident area through said intermediate transparent layer, said first band-pass layer supplied with said incident light beam for passing said first outgoing light beam towards said first exit area and for reflecting the incident light beam except said first outgoing light beam as a reflected light beam towards said primary reflection layer to make said primary reflection layer reflect said reflected light beam towards said second subsidiary incident area through said intermediate transparent layer;

a second band-pass layer interposed between said intermediate transparent layer and said second incident planar surface and formed on said second subsidiary incident area with said first outgoing and said second incident planar surfaces kept in substantially parallel to each other, said second band-pass layer supplied with said reflected light beam for passing said second outgoing light beam towards said second exit area;

first and second subsidiary reflection layers interposed between said intermediate transparent layer and said second incident planar surface and formed on said first and said second subsidiary reflection areas, respectively, with said first outgoing and said second incident planar surfaces kept in substantially parallel to each other; and

first and second semitransparent layers formed on said first and said second exit areas and supplied with said first and said second outgoing light beams for partially passing said first and said second outgoing light beams, respectively, and for partially reflecting said first and said second outgoing light beams towards said first and said second subsidiary reflection layers to make said first and said second subsidiary reflection layers reflect said first and said second outgoing light beams towards said first and said second semitransparent layers, respectively, each of said first and said second semitransparent layers thereby producing said plurality of the partial light beams for each of said first and said second outgoing light beams.

4. A beam splitter as claimed in claim 3, wherein said intermediate transparent layer has a refractive index which is substantially equal to that of said first transparent block.

5. A beam splitter supplied with a single incident light beam having first, second, and third wavelength components for splitting said incident light beam into first, second, and third outgoing light beams having said first, said second, and said third wavelength components, respectively, and for splitting each of said first through said third outgoing light beams into a plurality of partial light beams, said beam splitter comprising:

a first transparent block having first incident and first outgoing planar surfaces substantially parallel to each other, said first incident planar surface having a primary incident area and a primary reflection area, said primary incident area being for receiving said incident light beam to direct said incident light beam towards said first outgoing planar surface;

a primary reflection layer formed on said primary reflection area;

a second transparent block having second incident and second outgoing planar surfaces substantially parallel to each other, said second incident planar surface having first and second subsidiary incident areas, first, second, and third subsidiary reflection areas, and a remaining area, said second outgoing planar surface having first, second, and third exit areas;

an intermediate transparent layer interposed between said first outgoing and said second incident planar surfaces;

a first band-pass layer interposed between said intermediate transparent layer and said second incident planar surface and formed on said first subsidiary incident area with said first outgoing and said second incident planar surfaces kept in substantially parallel to each other and with said incident light beam directed towards said first subsidiary incident area through said intermediate transparent layer, said first band-pass layer supplied with said incident light beam for passing said first outgoing light beam towards said first exit area and for reflecting said second and said third outgoing light beams towards said primary reflection layer to make said primary reflection layer reflect said second and said third outgoing light beams towards said second incident area through said intermediate transparent layer;

a second band-pass layer interposed between said intermediate transparent layer and said second incident planar surface and formed on said second subsidiary incident area with said first outgoing and said second incident planar surfaces kept in substantially parallel to each other, said second band-pass layer supplied with said second and said third outgoing light beams for passing said second outgoing light beam towards said second exit area and for reflecting said third outgoing light beam towards said primary reflection layer to make said primary reflection layer reflect said third outgoing light beam towards said third exit area through said remaining area;

first, second, and third subsidiary reflection layers interposed between said intermediate transparent layer and said second incident planar surface and formed on said first through said third subsidiary reflection areas, respectively, with said first outgoing and said second incident planar surfaces kept in substantially parallel to each other; and

first, second, and third semitransparent layers formed on said first through said third exit areas and supplied with said first through said third outgoing light beams for partially passing said first through said third outgoing light beams, respectively, and for partially reflecting said first through said third outgoing light beams towards said first through said third subsidiary reflection layers to make said first through said third subsidiary reflection layers reflect said first through said third outgoing light beams towards said first through said third semitransparent layers, respectively, each of said first through said third semitransparent layers thereby producing said plurality of the partial light beams for each of said first through said third outgoing light beams.

6. A beam splitter as claimed in claim 5, wherein said first and said second transparent blocks and said intermediate transparent layer have refractive indexes which are substantially equal to one another.

7. A beam splitter supplied with a single incident light beam having first, second, third, and other wavelength components for splitting said incident light beam into first, second, and third outgoing light beams having said first, said second, and said third wavelength components, respectively, and for splitting each of said first through said third outgoing light beams into a plurality of partial light beams, said beam splitter comprising:

a first transparent block having first incident and first outgoing planar surfaces substantially parallel to each other, said first incident planar surface having a primary incident area and a primary reflection area, said primary incident area being for receiving said incident light beam to direct said incident light beam towards said first outgoing planar surface;

a primary reflection layer formed on said primary reflection area;

a second transparent block having second incident and second outgoing planar surfaces substantially parallel to each other, said second incident planar surface having first, second, and third subsidiary incident areas and first, second, and third subsidiary reflection areas, said second outgoing planar surface having first, second, and third exit areas;

an intermediate transparent layer interposed between said first outgoing and said second incident planar surfaces;

a first band-pass layer interposed between said intermediate transparent layer and said second incident planar surface and formed on said first subsidiary incident area with said first outgoing and said second incident planar surfaces kept in substantially parallel to each other and with said incident light beam directed towards said first subsidiary incident area through said intermediate transparent layer, said first band-pass layer supplied with said incident light beam for passing said first outgoing light beam towards said first exit area and for reflecting the incident light beam except said first outgoing light beam as a first reflected light beam towards said primary reflection layer to make said primary reflection layer reflect said first reflected light beam towards said second subsidiary incident area through said intermediate transparent layer;

a second band-pass layer interposed between said intermediate transparent layer and said second incident planar surface and formed on said second subsidiary incident area with said first outgoing and said second incident planar surfaces kept in substantially parallel to each other, said second band-pass layer supplied with said first reflected light beam for passing said second outgoing light beam towards said second exit area and for reflecting the incident light beam except said first and said second outgoing light beams as a second reflected light beam towards said primary reflection layer to make said primary reflection layer reflect said second reflected light beam towards said third subsidiary incident area through said intermediate transparent layer;

a third band-pass layer interposed between said intermediate transparent layer and said second incident planar surface and formed on said third subsidiary incident area with said first outgoing and said second incident planar surfaces kept in substantially parallel to each other, said third band-pass layer supplied with said second reflected light beam for passing said third outgoing light beam towards said third exit area;

first, second, and third subsidiary reflection layers interposed between said intermediate transparent layer and said second incident planar surface and formed on said first through said third subsidiary reflection areas, respectively, with said first outgoing and said second incident planar surfaces kept in substantially parallel to each other; and

first, second, and third semitransparent layers formed on said first through said third exit areas and supplied with said first through said third outgoing light beams for partially passing said first through said third outgoing light beams, respectively, and for partially reflecting said first through said third outgoing light beams towards said first through said third subsidiary reflection layers to make said first through said third subsidiary reflection layers reflect said first through said third outgoing light beams towards said first through said third semitransparent layers, respectively, each of said first through said third semitransparent layers thereby producing said plurality of the partial light beams for each of said first through said third outgoing light beams.

8. A beam splitter as claimed in claim 7, wherein said intermediate transparent layer has a refractive index which is substantially equal to that of said first transparent block.

9. A beam splitter supplied with a single original incident light beam having first, second, . . . , (N-1)-th, N-th, and other wavelength components for splitting said original incident light beam into first, second, . . . , (N-1)-th, and N-th outgoing light beams having said first through said N-th wavelength components, respectively, and for splitting each of said first through said N-th outgoing light beams into a plurality of partial light beams, where N represents an integer greater than three, said beam splitter comprising:

a first transparent block having first incident and first outgoing planar surfaces substantially parallel to each other, said first incident planar surface having a primary incident area and a primary reflection area, said primary incident area being for receiving said original incident light beam to direct said original incident light beam towards said first outgoing planar surface;

a primary reflection layer formed on said primary reflection area;

a second transparent block having second incident and second outgoing planar surfaces substantially parallel to each other, said second incident planar surface having first, second, . . . , (N-1)-th, and N-th subsidiary incident areas and first, second, . . . , (N-1)-th, and N-th subsidiary reflection areas, said second outgoing planar surface having first, second, . . . , (N-1)-th, and N-th exit areas;

an intermediate transparent layer interposed between said first outgoing and said second incident planar surfaces;

first, second, . . . , (N-1)-th, and N-th band-pass layers interposed between said intermediate transparent layer and said second incident planar surface and formed on said first through said N-th subsidiary incident areas, respectively, with said first outgoing and said second incident planar surfaces kept in substantially parallel to each other and with said original incident light beam directed towards said first subsidiary incident area through said intermediate layer, said first through said N-th band-pass layers supplied with first, second, . . . , (N-1)-th, and N-th incident light beams for passing said first through said N-th outgoing light beams towards said first through said N-th exit areas, respectively, said first through said (N-1)-th band-pass layers being for reflecting first through (N-1)-th reflected light beams towards said primary reflection layer to make said primary reflection layer reflect, as said second through said N-th incident light beams, said first through said (N-1)-th reflected light beams towards said second through said N-th exit areas through said intermediate transparent layer, respectively, said first incident light beam being equivalent to said original incident light beam, said second incident light beam being equivalent to the original incident light beam except said first outgoing light beam, said N-th incident light beam being equivalent to the original light beam except said first through said (N-1)-th outgoing light beams;

first, second, . . . , (N-1)-th, and N-th subsidiary reflection layers interposed between said intermediate transparent layer and said second incident planar surface and formed on said first through said N-th subsidiary reflection areas, respectively, with said first outgoing and said second incident planar surfaces kept in substantially parallel to each other; and

first, second, . . . , (N-1)-th, and N-th semitransparent layers formed on said first through said N-th exit areas and supplied with said first through said N-th outgoing light beams for partially passing said first through said N-th outgoing light beams, respectively, and for partially reflecting said first through said N-th outgoing light beams towards said first through said N-th subsidiary reflection layers to make said first through said N-th subsidiary reflection layers reflect said first through said N-th outgoing light beams towards said first through said N-th semitransparent layers, respectively, each of said first through said N-th semitransparent layers thereby producing said plurality of the partial light beams for each of said first through said N-th outgoing light beams.

10. A beam splitter as claimed in claim 9, wherein said intermediate transparent layer has a refractive index which is substantially equal to that of said first transparent block.