Abstract: An image display device having an RGB illuminating module that includes a diffractive beam combiner. The diffractive beam combiner includes a first light source arranged to provide a first light beam having red color and a second light source arranged to provide a second light beam having green color. A centerline of the first light beam and a centerline of the second light beam are arranged to intersect at an intersection point. A diffractive output grating is located in the vicinity of the intersection point. The diffractive output grating is arranged to form an output light beam by diffracting light of the first light beam and light of the second light beam substantially in the same direction.

Abstract: A device including a combination of a waveguide and a grating arranged to provide a spectral reflectance. The grating has a plurality of diffractive features in a first region and in a second region such that in the first region, a local average of a length of a period of the diffractive features substantially increases with increasing distance from an origin, and in the second region, the local average of the length of the period of the diffractive features substantially decreases with increasing distance from an origin. The origin is located at an end of the device.

Abstract: A nonlinear crystal includes a plurality of poled zones implemented in a nonlinear material. The crystal has a first region and a second region. In the first region, the local average of a length of a period of the poled zones substantially increases with increasing distance from an origin. In the second region, the local average of the length of the period of the poled zones substantially decreases with increasing distance from the origin. The origin is located at an end of the crystal.

Abstract: A light source including a light emitting unit, a nonlinear medium, and a resonant grating. The light emitting unit is arranged to emit a first light into the nonlinear medium. The nonlinear medium is arranged to generate a second light such that an optical frequency of the second light is higher than an optical frequency of the first light. The resonant grating is arranged to stabilize an optical frequency of the first light by providing optical feedback to the light emitting unit.

Abstract: An image display device having an RGB illuminating module that includes a diffractive beam combiner. The diffractive beam combiner includes a first light source arranged to provide a first light beam having red color and a second light source arranged to provide a second light beam having green color. A centerline of the first light beam and a centerline of the second light beam are arranged to intersect at an intersection point. A diffractive output grating is located in the vicinity of the intersection point. The diffractive output grating is arranged to form an output light beam by diffracting light of the first light beam and light of the second light beam substantially in the same direction.

Abstract: A light emitting device including a waveguide having an electrically pumped gain region, a saturable absorber, a nonlinear crystal, an inclined mirror, and a light-concentrating structure. Light pulses emitted from the gain region are reflected by the inclined mirror and focused by the light-concentrating structure into the nonlinear crystal in order to generate frequency-converted light pulses. The gain region, the saturable absorber, the light-concentrating structure and the inclined mirror are implemented on or in a common substrate. The resulting structure is stable and compact, and allows on-wafer testing of produced emitters. The folded structure allows easy alignment of the nonlinear crystal.

Abstract: A light source including a light emitting unit, a nonlinear medium, and a resonant grating. The light emitting unit is arranged to emit a first light into the nonlinear medium. The nonlinear medium is arranged to generate a second light such that an optical frequency of the second light is higher than an optical frequency of the first light. The resonant grating is arranged to stabilize an optical frequency of the first light by providing optical feedback to the light emitting unit.

Abstract: The invention is a single-crystal passively mode-locked semiconductor vertical-external-cavity surface-emitting laser (VECSEL). The device can be a single emitter or an array of emitters. The VECSEL structure is grown on a GaAs, InP or GaSb substrate. The device consists of an active region with a number of quantum wells (QW) made of GaInAs, GaInAsP, GaInNAs, GaInNAsSb, AlGaAs or GaAsP. The fundamental lasing wavelength is chosen by the gain material. The gain region is sandwiched between the bottom reflector with reflectivity close to 100% and a partial reflector. A semiconductor spacer layer made of e.g. GaAs or AlGaAs is separating the gain region and a semiconductor saturable absorber. The saturable absorber consists of one or more quantum wells made of GaInAs, GaInAsP, GaInNAs, GaInNAsSb, AlGaAs or GaAsP and a second partial reflector.

Abstract: A light emitting device including a waveguide having an electrically pumped gain region, a saturable absorber, a nonlinear crystal, an inclined mirror, and a light-concentrating structure. Light pulses emitted from the gain region are reflected by the inclined minor and focused by the light-concentrating structure into the nonlinear crystal in order to generate frequency-converted light pulses. The gain region, the saturable absorber, the light-concentrating structure and the inclined minor are implemented on or in a common substrate. The resulting structure is stable and compact, and allows on-wafer testing of produced emitters. The folded structure allows easy alignment of the nonlinear crystal.

Abstract: A light emitting device including an array of light emitters to emit first light pulses. Each of the light emitters includes a saturable absorber and a waveguide having an electrically pumped gain region to emit the first light pulses. At least one reflector structure reflects the first light pulses into a nonlinear crystal by changing the direction of the first light pulses by an angle that is in a range of 70 to 110 degrees. The reflector structure includes a sub-wavelength grating structure to change the polarization of the first light pulses. A nonlinear crystal generates second light pulses such that the optical frequency of the second light pulses is two times the optical frequency of the first light pulses.

Abstract: A light emitting device including an array of light emitters to emit first light pulses. Each of the light emitters includes a saturable absorber and a waveguide having an electrically pumped gain region to emit the first light pulses. At least one reflector structure reflects the first light pulses into a nonlinear crystal by changing the direction of the first light pulses by an angle that is in a range of 70 to 110 degrees. The reflector structure includes a sub-wavelength grating structure to change the polarization of the first light pulses. A nonlinear crystal generates second light pulses such that the optical frequency of the second light pulses is two times the optical frequency of the first light pulses.

Abstract: A light emitting device comprises a waveguide having an electrically pumped gain region, a nonlinear medium, and an inclined mirror. Light pulses emitted from the gain region are reflected by the inclined mirror into the nonlinear medium in order to generate frequency-doubled light pulses. The gain region and the inclined mirror are implemented on the same substrate. The resulting structure is stable and compact, and allows on-wafer testing of produced emitters. The folded structure allows easy alignment of the nonlinear crystal.

Abstract: A light emitting device comprises a waveguide having an electrically pumped gain region, a nonlinear medium, and an inclined mirror. Light pulses emitted from the gain region are reflected by the inclined mirror into the nonlinear medium in order to generate frequency-doubled light pulses. The gain region and the inclined mirror are implemented on the same substrate. The resulting structure is stable and compact, and allows on-wafer testing of produced emitters. The folded structure allows easy alignment of the nonlinear crystal.