Abstract: The light emitting device includes a semiconductor light emitting element including a first reflector, a resonator spacer including an active layer, and a second reflector stacked in this order over a semiconductor substrate. The semiconductor light emitting element includes a saturable absorption layer provided between the semiconductor substrate and the second reflector. The semiconductor light emitting element is configured to emit light having a profile that has a maximum peak value and converges to a stable value of a predetermined light intensity after the maximum peak value.

Abstract: A photoelectric conversion element includes a first reflecting mirror provided on a substrate, a resonator provided on the first reflecting mirror, and a second reflecting mirror provided on the resonator. The first reflecting mirror includes a distributed Bragg reflector (DBR) including a plurality of semiconductor layers. A photoelectric conversion layer is provided in at least one layer of the plurality of semiconductor layers.

Abstract: A semiconductor light-emitting element having a structure in which a substrate, a first reflector, a resonator cavity including an active layer, a second reflector and a tunnel junction portion are stacked in this sequence, comprising: a first current constriction portion configured with an oxidation constriction layer; and a second current constriction portion including the tunnel junction portion, wherein a width d2 of the second current constriction portion is smaller than a width d1 of the first current constriction portion.

Abstract: A light source device in which a plurality of semiconductor light-emitting elements are disposed, each of the plurality of semiconductor light-emitting elements being configured with a first reflector, a resonator cavity including an active layer, and a second reflector which are stacked in this sequence on a semiconductor substrate, wherein in each of the semiconductor light-emitting elements, an electric contact region for supplying carriers to the active layer is disposed on a surface of the second reflector on an opposite side thereof to the active layer, and wherein the plurality of semiconductor light-emitting elements include a first semiconductor light-emitting element of which shape of the contact region is a first shape, and a second semiconductor light-emitting element of which shape of the contact region is a second shape which is different from the first shape.

Abstract: A semiconductor light-emitting element having a structure in which a substrate, a first reflector, a resonator cavity including an active layer, a second reflector and a transparent conductive film are stacked in this sequence, the semiconductor light-emitting element comprising: a first current constriction portion configured with an oxidation constriction layer; and a second current constriction portion configured with an insulation film, which is formed on an upper face of the second reflector and has an opening, and a contact portion between the transparent conductive film and a semiconductor layer with which the transparent conductive film is in contact, wherein a width d2 of the second current constriction portion is smaller than a width d1 of the first current constriction portion.

Abstract: The disclosed light source device includes a light emitting element including a first reflector, a second reflector, and a resonator spacer portion provided between the first reflector and the second reflector and including an active layer, and emits a first light as a laser beam and a second light as a spontaneous emission light, a light receiving element that determines an amount of the second light, and a determination unit that determines a timing at which the first light oscillates based on a decrease in the amount of the second light determined by the light receiving element.

Abstract: A light-receiving element, comprising a plurality of photodiodes formed by stacking in this sequence, a lower reflection mirror, a resonator including a photoelectric conversion layer, and an upper reflection mirror on a semiconductor substrate, wherein the plurality of photodiodes share the semiconductor substrate and the lower reflection mirror, the plurality of photodiodes includes a first photodiode having a resonance wavelength ?1 and a second photodiode having a resonance wavelength ?2 that is larger than the resonance wavelength ?1, and a reflectance of the lower reflection mirror has a first peak corresponding to the resonance wavelength ?1 and a second peak corresponding to the resonance wavelength ?2.

Abstract: The light emitting element according to the present disclosure comprises a first active layer that emits light having a first wavelength by injecting current, a second active layer that emits light having a second wavelength different from the first wavelength by absorbing the light having the first wavelength, and a first reflecting mirror in which a reflectance of light having the first wavelength is higher than a reflectance of light having the second wavelength, wherein the first reflecting mirror is disposed at a position closer to an emission end, from which the light emitted by the first active layer or the second active layer exits outside, than the first active layer and the second active layer.

Abstract: A light-emitting thyristor includes a layered structure having a semiconductor DBR layer, a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductive type, a third semiconductor layer, and a fourth semiconductor layer of the second conductivity type in this order on a semiconductor substrate, the third semiconductor layer has at least one fifth semiconductor layer of the first conductivity type and a multi-quantum well structure, the fifth semiconductor layer is present between the second semiconductor layer and the multi-quantum well structure, the multi-quantum well structure is formed of barrier layers and quantum well layers, and the number of the quantum well layers is greater than or equal to 10.

Abstract: A photoelectric conversion element includes a first reflecting mirror provided on a substrate, a resonator provided on the first reflecting mirror, and a second reflecting mirror provided on the resonator. The first reflecting mirror includes a distributed Bragg reflector (DBR) including a plurality of semiconductor layers. A photoelectric conversion layer is provided in at least one layer of the plurality of semiconductor layers.

Abstract: A light-receiving element, comprising a plurality of photodiodes formed by stacking in this sequence, a lower reflection mirror, a resonator including a photoelectric conversion layer, and an upper reflection mirror on a semiconductor substrate, wherein the plurality of photodiodes share the semiconductor substrate and the lower reflection mirror, the plurality of photodiodes includes a first photodiode having a resonance wavelength ?1 and a second photodiode having a resonance wavelength ?2 that is larger than the resonance wavelength ?1, and a reflectance of the lower reflection mirror has a first peak corresponding to the resonance wavelength ?1 and a second peak corresponding to the resonance wavelength ?2.

Abstract: A light-emitting thyristor includes a layered structure having a semiconductor DBR layer, a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductive type, a third semiconductor layer, and a fourth semiconductor layer of the second conductivity type in this order on a semiconductor substrate, the third semiconductor layer has at least one fifth semiconductor layer of the first conductivity type and a multi-quantum well structure, the fifth semiconductor layer is present between the second semiconductor layer and the multi-quantum well structure, the multi-quantum well structure is formed of barrier layers and quantum well layers, and the number of the quantum well layers is greater than or equal to 10.

Abstract: A light emitting thyristor includes a stack structure having first to fourth semiconductor layers, and the third semiconductor layer includes at least a fifth semiconductor layer in contact with the second semiconductor layer and a sixth semiconductor layer in this order from the semiconductor substrate side. The sixth semiconductor layer is a layer having the smallest bandgap in all the layers forming the stack structure, and a difference ?Eg in bandgap between the fifth semiconductor layer and the sixth semiconductor layer is greater than or equal to 0.05 eV and less than or equal to 0.15 eV.

Abstract: A light emitting device, particularly a super luminescent diode, includes an active layer provided between upper and lower electrodes for injecting electric current into the active layer. The active layer functions as an optical waveguide and has first and second edge faces for emitting light. The device further includes first and second light receiving sections for receiving light emitted from the first and second edge faces respectively and generating first and second pieces of optical information respectively and a control section for controlling the current injection amount into the active layer from the upper electrode according to the first and second pieces of optical information. The optical output and the spectral shape of the device can be easily, accurately and reliably controlled in a short period of time.

Abstract: A light emitting thyristor includes a stack structure having first to fourth semiconductor layers, and the third semiconductor layer includes at least a fifth semiconductor layer in contact with the second semiconductor layer and a sixth semiconductor layer in this order from the semiconductor substrate side. The sixth semiconductor layer is a layer having the smallest bandgap in all the layers forming the stack structure, and a difference ?Eg in bandgap between the fifth semiconductor layer and the sixth semiconductor layer is greater than or equal to 0.05 eV and less than or equal to 0.15 eV.

Abstract: Provided is a photonic device in which emission intensity in a short wavelength region is suppressed even in the case of increasing carrier injection density so as to obtain a wide spectrum half-maximum width as well as a high output. The photonic device includes: a first cladding layer; a second cladding layer; and an active layer including an emitting layer and a barrier layer and being provided between the first cladding layer and the second cladding layer, the emitting layer emitting light in a spectrum having a center wavelength ?c and a spectrum half-maximum width ??, in which at least one of the first cladding layer and the second cladding layer includes a light absorbing part for absorbing light having a wavelength of ?s or less represented by the following Expression (1): ?s<(?c?(??/2))??(1).

Abstract: A light emitting device, particularly a super luminescent diode, includes an active layer provided between upper and lower electrodes for injecting electric current into the active layer. The active layer functions as an optical waveguide and has first and second edge faces for emitting light. The device further includes first and second light receiving sections for receiving light emitted from the first and second edge faces respectively and generating first and second pieces of optical information respectively and a control section for controlling the current injection amount into the active layer from the upper electrode according to the first and second pieces of optical information. The optical output and the spectral shape of the device can be easily, accurately and reliably controlled in a short period of time.

Abstract: A signs-of-deterioration detector for a semiconductor laser includes a first light receiving section that acquires first information relating to an optical output of the semiconductor laser and a second light receiving section that acquires second information relating to an intensity distribution of the emission pattern below the lasing threshold of the semiconductor laser. The detector also includes a holding section that holds the first information and the second information at a predetermined time point T1. The detector further includes a deciding section that decides the presence or absence of signs of rapid decrease of the optical output of the semiconductor laser by comparing the first information and the second information at at least one time point Tn (T1<Tn), with those at the time point T1.

Abstract: A luminescent device including an upper electrode layer, a lower electrode layer and an active layer provided between these electrode layers, the device having such a structure that at least one electrode layer of the upper electrode layer and the lower electrode layer is provided in an in-plane direction of the active layer being divided into plural electrodes, current is injected into plural different regions of the active layer by the plural electrodes to cause emission in plural luminescent regions, and light emitted from one luminescent region of the plural luminescent regions enters in another luminescent region and exits. The device further includes a light receiving portion for detecting light that is emitted from one luminescent region of the plural luminescent regions and does not go through another luminescent region.

Abstract: An acoustic signal receiving apparatus including: a Fabry-Perot sensor including a Fabry-Perot interferometer configured to convert an acoustic wave into a light intensity signal; a control unit configured to set a first wavelength and a second wavelength; a detecting unit configured to convert light intensities obtained by irradiation of the Fabry-Perot sensor with light from the first light source and the second light source into electric signals; and a signal processing unit configured to acquire a difference between an electric signal corresponding to the first wavelength and an electric signal corresponding to the second wavelength, wherein the control unit is configured to set the first wavelength and the second wavelength so that differential values of reflectivity spectrum of the Fabry-Perot sensor are different at the first wavelength and the second wavelength.