Compact illumination system with improved optical performance

The optical system of claim 5 wherein:

• the light source includes a first light source optically coupled to the first optical input surface and a second light source optically coupled to the second optical input surface;
• the telecentric lens configuration is disposed optically between the SLM and the second optical output surface such that:
• light from the first light source enters through the first optical input surface to be incident on the first polarization-selective surface, the first polarization light is reflected out of the optical device through the second optical output surface, transmitted through the telecentric lens configuration such that chief rays of angle fields impinge on the SLM normally, reflected by the SLM in the second polarization, transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, transmitted through the second polarization-selective surface, and outputted out of the optical device through the first optical output surface;
• and
• light from the second light source enters through the second optical input surface to be incident on the second polarization-selective surface, the first polarization light is reflected out of the optical device through the second optical output surface, transmitted through the telecentric lens configuration such that chief rays of angle fields impinge on the SLM normally, reflected by the SLM in the second polarization, transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, transmitted through the first polarization-selective surface, and outputted out of the optical device through the first optical output surface.

The optical system of claim 5, comprising:

• a first prism and a second prism;
• the mirror includes a first mirror optically disposed between the first polarization-selective surface and the first prism, and a second mirror optically disposed between the second polarization-selective surface and the second prism;
• the light source includes a first light source optically coupled to the first prism and a second light source optically coupled to the second prism;
• the telecentric lens configuration is disposed optically between the SLM and the second optical output surface such that:
• light from the first light source travels through the first prism to be incident on the first mirror, reflected to the first polarization-selective surface, the first polarization light being reflected out of the optical device through the second optical output surface, transmitted through the telecentric lens configuration such that chief rays of angle fields impinge on the SLM normally, reflected by the SLM in the second polarization, transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, transmitted through the second polarization-selective surface, and outputted out of the optical device through the first optical output surface;
• and
• light from the second light source travels through the second prism to be incident on the second mirror, reflected to the second polarization-selective surface, the first polarization light being reflected out of the optical device through the second optical output surface, transmitted through the telecentric lens configuration such that chief rays of angle fields impinge on the SLM normally, reflected by the SLM in the second polarization, transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, transmitted through the first polarization-selective surface, and outputted out of the optical device through the first optical output surface.

An The optical system of claim 5, comprising:

• a first waveguide and a second waveguide;
• the mirror includes a first mirror optically disposed between the first polarization-selective surface and the first waveguide, and a second mirror optically disposed between the second polarization-selective surface and the second waveguide;
• a third waveguide and third mirror optically coupled to the second waveguide;
• a polarizing beam splitter (PBS) optically coupled to the first waveguide and the third waveguide;
• a polarization rotation device optically coupled to the third waveguide;
• the light source optically coupled to the PBS;
• the telecentric lens configuration is disposed optically between the SLM and the second optical output surface such that:
• first polarization light from the light source is reflected by the PBS, travels through the first waveguide to be incident on the first mirror, reflected to the first polarization-selective surface, the first polarization light being reflected out of the optical device through the second optical output surface, transmitted through the telecentric lens configuration such that chief rays of angle fields impinge on the SLM normally, reflected by the SLM in the second polarization, transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, transmitted through the second polarization-selective surface, and outputted out of the optical device through the first optical output surface;
• and
• second polarization light from the light source is transmitted by the PBS to travel through an optical path including traveling through the third waveguide, being reflected by the third mirror, traveling through the second waveguide to be incident on the second mirror, being reflected to the second polarization-selective surface, the polarization rotation device rotating polarization of the second polarization light to the first polarization along the optical path such that the first polarization light is reflected out of the optical device through the second optical output surface, transmitted through the telecentric lens configuration such that chief rays of angle fields impinge on the SLM normally, reflected by the SLM in the second polarization, transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, transmitted through the first polarization-selective surface, and outputted out of the optical device through the first optical output surface.

An optical system comprising:

• an optical device comprising:
• a device body having a first optical input surface disposed at a first end of the device body and a second optical input surface disposed at a second end of the device body opposite the first end, a first optical output surface disposed at a first side of the device body and a second optical output surface disposed at a second side of the device body opposite the first side, an optical axis of the optical device orthogonal to the first optical output surface and the second optical output surface;
• a first polarization-selective surface configured to reflect a first polarization of incident light and transmit a second polarization of incident light orthogonal to the first polarization, the first polarization-selective surface disposed between the first and second optical input surfaces at a first angle α relative to the optical axis such that light entering the optical device through the first optical input surface is incident on the first polarization-selective surface and the first polarization of incident light is reflected out of the optical device through the second optical output surface;
• a second polarization-selective surface configured to reflect the first polarization of incident light and transmit the second polarization of incident light orthogonal to the first polarization, the second polarization-selective surface disposed between the first and second optical input surfaces at a second angle β relative to the optical axis such that light entering the optical device through the second optical input surface is incident on the second polarization-selective surface and the first polarization of incident light is reflected out of the optical device through the second optical output surface, wherein β is approximately equal to −α;
• a spatial light modulator (SLM) disposed on a second optical output surface side of the optical device;
• a light source optically coupled to the first optical input surface;
• a mirror disposed adjacent the second optical input surface;
• a quarter-wave plate optically coupled between the mirror and the second optical input surface;
• a telecentric lens configuration disposed optically between the SLM and the second optical output surface such that:
• light from the light source enters through the first optical input surface to be incident on the first polarization-selective surface,
• wherein first polarization light from the light source is reflected by the first polarization-selective surface out of the optical device through the second optical output surface, transmitted through the telecentric lens configuration such that chief rays of angle fields impinge on the SLM normally, reflected by the SLM in the second polarization, transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, transmitted through the second polarization-selective surface, and outputted out of the optical device through the first optical output surface;
• and
• wherein second polarization light from the light source is transmitted by the first polarization-selective surface and the second polarization-selective surface, exits through the second optical input surface, passes the quarter-wave plate to rotate polarization a quarter wave, is reflected by the mirror, passes the quarter-wave plate a second time to rotate polarization an additional quarter wave to the first polarization, reenters through the second optical input surface to be incident on the second polarization-selective surface, the first polarization light is reflected out of the optical device through the second optical output surface, transmitted through the telecentric lens configuration such that chief rays of angle fields impinge on the SLM normally, reflected by the SLM in the second polarization, transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, transmitted through the first polarization-selective surface, and outputted out of the optical device through the first optical output surface.

The optical system of claim 12,

• the light source includes a first light source optically coupled to the first optical input surface and a second light source optically coupled to the second optical input surface;
• wherein the telecentric lens configuration is disposed optically between the SLM and the second optical output surface such that:
• light from the first light source enters through the first optical input surface to be incident on the first polarization-selective surface, the first polarization light is reflected out of the optical device through the second optical output surface, transmitted through the telecentric lens configuration such that chief rays of angle fields impinge on the SLM normally, reflected by the SLM in the second polarization, transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, transmitted through the second polarization-selective surface, and outputted out of the optical device through the first optical output surface;
• and
• light from the second light source enters through the second optical input surface to be incident on the second polarization-selective surface, the first polarization light is reflected out of the optical device through the second optical output surface, transmitted through the telecentric lens configuration such that chief rays of angle fields impinge on the SLM normally, reflected by the SLM in the second polarization, transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, transmitted through the first polarization-selective surface, and outputted out of the optical device through the first optical output surface.

The optical system of claim 12, comprising:

• a first prism and a second prism;
• the mirror includes a first mirror optically disposed between the first polarization-selective surface and the first prism, and a second mirror optically disposed between the second polarization-selective surface and the second prism;
• the light source includes a first light source optically coupled to the first prism and a second light source optically coupled to the second prism;
• the telecentric lens configuration disposed optically between the SLM and the second optical output surface such that:
• light from the first light source travels through the first prism to be incident on the first mirror, reflected to the first polarization-selective surface, the first polarization light being reflected out of the optical device through the second optical output surface, transmitted through the telecentric lens configuration such that chief rays of angle fields impinge on the SLM normally, reflected by the SLM in the second polarization, transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, transmitted through the second polarization-selective surface, and outputted out of the optical device through the first optical output surface;
• and
• light from the second light source travels through the second prism to be incident on the second mirror, reflected to the second polarization-selective surface, the first polarization light being reflected out of the optical device through the second optical output surface, transmitted through the telecentric lens configuration such that chief rays of angle fields impinge on the SLM normally, reflected by the SLM in the second polarization, transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, transmitted through the first polarization-selective surface, and outputted out of the optical device through the first optical output surface.

The optical system of claim 12, comprising:

• a first waveguide and a second waveguide;
• the mirror includes a first mirror optically disposed between the first polarization-selective surface and the first waveguide, and a second mirror optically disposed between the second polarization-selective surface and the second waveguide;
• a third waveguide and third mirror optically coupled to the second waveguide;
• a polarizing beam splitter (PBS) optically coupled to the first waveguide and the third waveguide;
• a polarization rotation device optically coupled to the third waveguide;
• the light source optically coupled to the PBS;
• the telecentric lens configuration is disposed optically between the SLM and the second optical output surface such that:
• first polarization light from the light source is reflected by the PBS, travels through the first waveguide to be incident on the first mirror, reflected to the first polarization-selective surface, the first polarization light being reflected out of the optical device through the second optical output surface, transmitted through the telecentric lens configuration such that chief rays of angle fields impinge on the SLM normally, reflected by the SLM in the second polarization, transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, transmitted through the second polarization-selective surface, and outputted out of the optical device through the first optical output surface;
• and
• second polarization light from the light source is transmitted by the PBS to travel through an optical path including traveling through the third waveguide, being reflected by the third mirror, traveling through the second waveguide to be incident on the second mirror, being reflected to the second polarization-selective surface, the polarization rotation device rotating polarization of the second polarization light to the first polarization along the optical path such that the first polarization light is reflected out of the optical device through the second optical output surface, transmitted through the telecentric lens configuration such that chief rays of angle fields impinge on the SLM normally, reflected by the SLM in the second polarization, transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, transmitted through the first polarization-selective surface, and outputted out of the optical device through the first optical output surface.

An optical system comprising:

• an optical device comprising:
• a device body formed by adjoining at least three optical portions, each of the at least three optical portions made of an optically transparent material, the device body having a first optical input surface disposed at a first end of the device body and a second optical input surface disposed at a second end of the device body opposite the first end, a first optical output surface disposed at a first side of the device body and a second optical output surface disposed at a second side of the device body opposite the first side, an optical axis of the optical device orthogonal to the first optical output surface and the second optical output surface;
• one or more polarization-selective coatings or foils disposed between the at least three portions, wherein the one or more polarization-selective coatings or foils are configured to reflect a first polarization of incident light and transmit a second polarization of incident light orthogonal to the first polarization such that adjoining surfaces of the at least three optical portions form a first polarization-selective surface and a second polarization-selective surface;
• the first polarization-selective surface disposed between the first and second optical input surfaces at a first angle α relative to the optical axis such that the first polarization-selective surface reflects the first polarization of incident light out of the optical device through the second optical output surface;
• and
• the second polarization-selective surface disposed between the first and second optical input surfaces at a second angle β relative to the optical axis such that the second polarization-selective surface reflects the first polarization of incident light out of the optical device through the second optical output surface, wherein β is approximately equal to −α;
• a spatial light modulator (SLM) disposed on a second optical output surface side of the optical device;
• a light source optically coupled to the first optical input surface;
• a mirror disposed adjacent the second optical input surface;
• a quarter-wave plate optically coupled between the mirror and the second optical input surface;
• a telecentric lens configuration disposed optically between the SLM and the second optical output surface such that:
• light from the light source enters through the first optical input surface to be incident on the first polarization-selective surface,
• wherein first polarization light from the light source is reflected by the first polarization-selective surface out of the optical device through the second optical output surface, transmitted through the telecentric lens configuration such that chief rays of angle fields impinge on the SLM normally, reflected by the SLM in the second polarization, transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, transmitted through the second polarization-selective surface, and outputted out of the optical device through the first optical output surface;
• and
• wherein second polarization light from the light source is transmitted by the first polarization-selective surface and the second polarization-selective surface, exits through the second optical input surface, passes the quarter-wave plate to rotate polarization a quarter wave, is reflected by the mirror, passes the quarter-wave plate a second time to rotate polarization an additional quarter wave to the first polarization, reenters through the second optical input surface to be incident on the second polarization-selective surface, the first polarization light is reflected out of the optical device through the second optical output surface, transmitted through the telecentric lens configuration such that chief rays of angle fields impinge on the SLM normally, reflected by the SLM in the second polarization, transmitted through the telecentric lens configuration to enter the optical device through the second optical output surface, transmitted through the first polarization-selective surface, and outputted out of the optical device through the first optical output surface.

A method for an optical device, comprising:

• emitting light from one or more light sources;
• directing the emitted light towards first and second beam splitter surfaces of the optical device;
• reflecting first polarization light by the first and second beam splitter surfaces such that the first polarization light impinges on a spatial light modulator (SLM) at a normal incidence;
• modulating the first polarization light using the SLM to form an image;
• reflecting by the SLM image light in a second polarization orthogonal to the first polarization;
• and
• transmitting the second polarization light through the first and second beam splitter surfaces to be coupled out of the optical device;
• wherein the reflecting the first polarization light by the first and second beam splitter surfaces such that the first polarization light impinges on the SLM at the normal incidence includes:
• transmitting of the second polarization light by the first beam splitter surface and the second beam splitter surface;
• passing the second polarization light through a quarter-wave plate to rotate polarization a quarter wave;
• reflecting the quarter wave rotated light;
• passing the quarter wave rotated light through the quarter-wave plate a second time to rotate polarization an additional quarter wave to the first polarization;
• and
• reflecting of the first polarization light by the second beam splitter surface towards the SLM.