Abstract: A light source device according to the present disclosure includes a light source section, a first polarization split element for transmitting first light with a first polarization direction from the light source section and reflecting the first light with a second polarization direction, a first retardation element, a second polarization split element for reflecting the first light in the second polarization direction from the first retardation element, a second retardation element, and a light conversion device having a diffusion element for diffusing the first light from the second retardation element, a first wavelength conversion element for performing wavelength conversion on the first light to emit second light, and a substrate.

Abstract: A semiconductor optical modulator includes a modulation region and a non-modulation region. A first width of a first ground electrode in the non-modulation region is larger than a second width of the first ground electrode in the modulation region. A third width of a second ground electrode in the non-modulation region is larger than a fourth width of the second ground electrode in the modulation region. In the non-modulation region, a first insulating layer is disposed between a first optical waveguide and a first traveling wave electrode and between a second optical waveguide and a second traveling wave electrode. For this reason, a bandwidth of the semiconductor optical modulator can be widened.

Abstract: Alight source device according to the present disclosure includes a light source section for emitting first light, a first polarization split element for performing polarization split on the first light, a second polarization split element for reflecting the first light polarized in a first polarization direction and transmitting the first light polarized in a second polarization direction, a diffusion element for diffusing the first light from the first polarization split element, a wavelength conversion element for performing wavelength conversion on the first light entering the wavelength conversion element from the second polarization split element to emit second light, and an optical element having a flat-surface area and the concave-surface area.

Abstract: A light source device according to the present disclosure includes a first light source section for emitting first light in a first wavelength band, a first polarization split element for transmitting the first light polarized in a first polarization direction and reflecting the first light polarized in a second polarization direction, a second polarization split element for reflecting the first light with the first polarization direction, a diffusion element for diffusing the first light from the first polarization split element, a wavelength conversion element for emitting second light in a second wavelength band, a second light source section for emitting third light in a third wavelength band, a first optical element for reflecting the third light, and a second optical element for separating the second light into fourth light in a fourth wavelength band and a fifth light in the third wavelength band.

Abstract: A light source apparatus according to the present disclosure includes a first light source section that outputs first light, a second light source section that outputs second light, a first polarization separator that transmits the first light and the second light polarized in a first polarization direction and reflects the first light polarized in a second polarization direction, a second polarization separator that reflects the first light polarized in the first polarization direction, a first diffusion element that diffuses the first light incident from the first polarization separator, a wavelength converter that converts in terms of wavelength the first light and emits third light, and a second diffusion element that diffuses the second light incident from the second polarization separator.

Abstract: Alight source apparatus includes a light source section that outputs first light, a first polarization separator that separates the first light in terms of polarization, a second polarization separator that reflects in the second direction a portion of the first light polarized in the first polarization direction and transmits the other portion of the first light polarized in the first polarization direction, a diffusion element that diffuses the first light incident from the first polarization separator, a first wavelength converter that converts in terms of wavelength the portion of the first light incident from the second polarization separator and emits second light, and a second wavelength converter that converts in terms of wavelength the other portion of the first light incident from the second polarization separator and emits third light.

Abstract: A light source device includes a light source, a first polarization split element for transmitting first light from the light source which is polarized in a first polarization direction and reflecting the first light polarized in a second polarization direction, a first optical element for reflecting the first light from the first polarization split element, a diffusion element for diffusing the first light from the first polarization split element, a wavelength conversion element for performing wavelength conversion on the first light from the first optical element to emit second light, a second polarization split element which the second light enters from the first optical element, and which transmits the second light polarized in the first polarization direction and reflects the second light polarized in the second polarization direction, and a second optical element for reflecting the second light from the second polarization split element, polarized in the second polarization direction.

Abstract: A light source apparatus includes a light source section, a first optical layer that transmits first light polarized in a first polarization direction and incident from the light source section and reflects the first light polarized in a second polarization direction and incident from the light source section, a second optical layer that transmits the first light polarized in the first polarization direction and incident from the first optical layer, a third optical layer that transmits the first light polarized in the first polarization direction and incident from the second optical layer, a fourth optical layer that reflects the first light polarized in the first polarization direction and incident from the third optical layer, a diffusion element, and a wavelength converter.

Abstract: A light source device according to the present disclosure includes a light source section, a first polarization split element for transmitting first light with a first polarization direction from the light source section and reflecting the first light with a second polarization direction, a second polarization split element for transmitting the first light with the first polarization direction from the first polarization split element, a reflecting element for reflecting the first light with the second polarization direction from the first polarization split element, an optical element for reflecting the first light with the second polarization direction from the reflecting element, a wavelength conversion element for performing wavelength conversion on the first light from the optical element to emit second light, and a diffusion element for diffusely emitting the first light from the second polarization split element.

Abstract: A light source device includes a light source, an optical element for transmitting light from the light source which is polarized in a first polarization direction and reflecting the light polarized in a second polarization direction, a polarization split element for transmitting the light from the optical element which is polarized in first polarization direction and reflecting the light polarized in the second polarization direction, a wavelength conversion element for performing wavelength conversion on the light to emit second light in a second wavelength band, a diffusion element for diffusing the light, a first color separation element for separating light from the polarization split element into third light in a first wavelength band and fourth light in the second wavelength band, and a second color separation element for separating light from the optical element into fifth light in a third wavelength band and sixth light in a fourth wavelength band.

Abstract: A light source device according to the present disclosure includes a light source section, a first polarization split layer for transmitting first light polarized in a first polarization direction and reflecting the first light polarized in a second polarization direction, a first optical layer and a second polarization split layer for transmitting the first light polarized in the first polarization direction, a second optical layer for reflecting the first light polarized in the first polarization direction, a diffusion element, a wavelength conversion element for performing wavelength conversion on the first light to emit second light, and a first color separation element.

Abstract: An illuminator includes a light source that outputs first light having a first wavelength band, a wavelength converter that converts the first light into second light having a second wavelength band different from the first, a first optical element that reflects part of the first light to cause the reflected first light to be incident on the wavelength converter and transmits the other part of the first light and the second light, and a second optical element that reflects the other part of the first light having the first wavelength band and passing through the first optical element, the direction of the reflected light being the traveling direction of the second light having the second wavelength band and passing through the first optical element, and transmits the second light having the second wavelength band and emitted from the wavelength converter.

Abstract: A multi-mode interferometric optical waveguide device includes: a multi-mode interferometric optical waveguide which includes a first reflective surface; a first single-mode waveguide connected to the multi-mode interferometric optical waveguide; and a second single-mode waveguide connected to the multi-mode interferometric optical waveguide and oppose the first reflective surface. Consequently, the multi-mode interferometric optical waveguide device can propagate light from the first single-mode waveguide to the second single-mode waveguide, with further reduced optical losses.

Abstract: A light source apparatus according to the present disclosure includes a light source section, a first polarization separator that transmits in a first polarization component of the first light and reflects a second polarization component of the first light, a second polarization separator that reflects the first polarization component, a diffuser that diffuses the second polarization component and causes the diffused second polarization component, a first wavelength converter that converts the wavelength of the first polarization component into second light, and a second wavelength converter that is disposed in a position shifted in a fifth direction from a placement plane where the first polarization separator and the second polarization separator are placed, converts the wavelength of the excitation light into third light, and the second polarization separator transmits the first polarization component of the second light and reflects the second polarization component of the second light.

Abstract: An infrared light source radiates infrared light. An ATR prism receives, on a first end face, the infrared light radiated from the infrared light source, causes the received infrared light to pass therethrough while repeating total reflection off a second end face and a third end face, and emits the infrared light that has passed therethrough from the third end face. An infrared photodetector detects the intensity of the infrared light emitted from the ATR prism. Strain sensors, which are contact sensors of one type, are attached to the ATR prism and configured to detect a contact state between the ATR prism and a measurement skin.

Abstract: An illumination device including light source section for emitting first light in first wavelength band, optical element having first area for transmitting or reflecting part of first light, and second area for reflecting another part of first light when it's transmitted through first area or when first light is reflected by first area, first wavelength conversion element wherein first light emitted from first area enters, converts part of first light into second light in second wavelength band while diffusing another part of first light, and then emits result, and second wavelength conversion element wherein first light emitted from second area enters, and converts first light into third light in third wavelength band different from first and second wavelength bands, wherein first and second areas reflect third light when transmitting second light, and transmit third light when reflecting second light, and second area is disposed to surround periphery of first area.

Abstract: An illumination device includes a first light emitting element emitting first light in a first wavelength band, a wavelength conversion element converting a part of the first light into second light including a second wavelength band and a third wavelength band, diffusing another part of the first light, and emitting a result, a second light emitting element for emitting third light having the second wavelength band, a first optical element having a first area for reflecting the first light to enter the wavelength conversion element, reflecting fourth light having the second wavelength band out of the second light, and reflecting the third light, and a second area for transmitting the first light and the second light, and a second optical element for transmitting the first light to enter the first optical element, and reflecting the fourth light to enter the wavelength conversion element via the first area.

Abstract: An illumination device includes a light emitting element emitting first light, wavelength conversion element converting the first light into second, first optical element, second optical element having a first area transmitting the second light, and second area transmitting part of the first light and reflecting another part, and third optical element having a third area transmitting the second light, and fourth area transmitting part of the first light and reflecting another part. The first area first light transmittance in the second optical element is higher than that in the second area, the second optical element position made switchable between first and second positions, the third area first light transmittance in the third optical element is higher than that in the fourth area, the third optical element position is made switchable between third and fourth positions, and the fourth area first light transmittance is different from that in the second area.

Abstract: A projector includes a first light source device configured to emit first light having a first wavelength band, a second light source device configured to emit second light having a second wavelength band, a first light modulator configured to modulate the first light, and a second light modulator configured to modulate the second light. The first light source device includes a first light emitting element configured to emit excitation light and a wavelength converter configured to convert the excitation light into the first light. The second light source device includes a second light emitting element configured to emit the second light, a diffuser configured to diffuse the second light, and an optical element having an aspherical surface. The optical element is disposed on an optical path of the second light between the diffuser and the second light modulator and is configured to increase field curvature on the second light modulator.

Abstract: An optical transmission apparatus includes a first multilevel optical phase modulator and a first semiconductor optical amplifier. The first semiconductor optical amplifier includes a first active region having a first multiple quantum well structure. Assuming that a first number of layers of a plurality of first well layers is defined as n1 and a first length of the first active region is defined as L1 (?m): (a) n1=5 and 400?L1?563; (b) n1=6 and 336?L1?470; (c) n1=7 and 280?L1?432; (d) n1=8 and 252?L1?397; (e) n1=9 and 224?L1?351; or (f) n1=10 and 200?L1?297.