A laser light source includes: a laser diode chip including an emission layer, a substrate supporting the emission layer, and an emission end surface; a submount that includes a principal surface on which the laser diode chip is fixed and a pair of lens supports located at opposite sides with respect to the emission end surface of the laser diode chip; a lens bonded to the end surfaces of the pair of lens supports; and a semiconductor laser package housing the aforementioned elements. The laser diode chip is fixed to the submount with the emission layer being closer to the submount than is the substrate. The emission end surface of the laser diode chip is located outward with respect to an edge of the principal surface. The end surfaces of the pair of lens supports are located outward with respect to the first end surface of the laser diode chip.

A quantum cascade laser element includes: a semiconductor substrate; a semiconductor laminate formed on the semiconductor substrate to include an active layer having a quantum cascade structure and to have a first end surface and a second end surface facing each other in a light waveguide direction; a first electrode; a second electrode; an insulating film continuously formed from the second end surface to a region on a second end surface side of at least one surface of a surface on an opposite side of the first electrode from the semiconductor laminate and a surface on an opposite side of the second electrode from the semiconductor substrate; and a metal film formed on the insulating film to cover at least the active layer when viewed in the light waveguide direction. An outer edge of the metal film does not reach the one surface when viewed in the light waveguide direction.

A method for manufacturing a quantum cascade laser element includes: a step of forming a semiconductor layer on a first major surface of a semiconductor wafer; a step of removing a part of the semiconductor layer by etching such that each of portions of the semiconductor layer includes a ridge portion; a step of forming an insulating layer such that at least a part of a surface of the ridge portion is exposed; a step of embedding the ridge portion in each of metal plating layers; a step of flattening a surface of the metal plating layers by polishing in a state where a protective member is disposed; a step of forming an electrode layer on a second major surface of the semiconductor wafer; and a step of cleaving the semiconductor wafer and the semiconductor layer in a state where the protective member is removed.

A quantum cascade laser element includes: a semiconductor substrate; a semiconductor laminate having a first end surface and a second end surface; a first electrode; a second electrode; and an anti-reflection film formed on the first end surface. The semiconductor laminate is configured to oscillate laser light having a center wavelength of 7.5 μm or more. The anti-reflection film includes an insulating film being a CeO.sub.2 film formed on the first end surface, a first refractive index film being a YF.sub.3 film or a CeF.sub.3 film disposed on a side opposite the first end surface with respect to the insulating film, and a second refractive index film formed on the first refractive index film on a side opposite the first end surface with respect to the first refractive index film and having a refractive index of larger than 1.8.

A semiconductor laser includes an active layer which emits laser light and cladding layers being formed so as to sandwich the active layer. The active layer includes a quantum dot layer including a plurality of quantum dots, which respectively confine movements of carriers in the three-dimensional directions. The laser radar device includes a light projection part which projects laser light and a light receiving part which receives reflected light of the laser light. The light projection part includes the semiconductor laser and a scanner which reflects the laser light, emitted from the semiconductor laser, to form a scanning laser light.

Structures and methods for reducing the thermal resistance of quantum cascade laser (QCL) devices and QCL-based photonic integrated circuits (QCL-PIC) are provided. In various embodiments, the native substrate of QCL and QCL-PIC devices is replaced with a foreign substrate that has very high thermal conductivity, for example, using wafer bonding methods. In some examples, wafer bonding of processed, semi-processed, or unprocessed QCL and QCL-PIC epilayers or devices on their native substrate to a high-thermal-conductivity substrate is performed, followed by removal of the native substrate via selective etching, and performing additional device processing if necessary. Thereafter, in some embodiments, cleaving or dicing individual devices from the bonded wafers may be performed, for example, for mounting onto heat sinks.

The present disclosure relates to an integrated light receiving and emitting device combined with a control circuit wafer and a manufacturing method thereof. The integrated light receiving and emitting device combined with a control circuit wafer according to an exemplary embodiment of the present disclosure includes: a light receiving and emitting unit which has an integrated wafer structure in which a light emitting unit and a light receiving unit are vertically formed on one surface of a single semiconductor substrate by wafer patterning and a control circuit wafer which is combined with the light receiving and emitting unit by vertical bonding to be operated as a single chip device, in which the control circuit wafer is connected to the light emitting unit and the light receiving unit.

A directly-modulated laser diode with GSG coplanar electrodes comprises a semi-insulating semiconductor substrate, an N-type semiconductor layer, a light-emitting layer, a P-type semiconductor layer, an insulating layer of dielectric material, a P-type electrode, and two N-type electrodes. It is characterized in that the two N-type electrodes are disposed on the N-type semiconductor layer and connected to the top of insulating layer along the sidewall to form a coplanar surface, the P-type electrode and the two N-type electrodes are GSG (ground-signal-ground) coplanar electrodes. The disclosure uses a hybrid coplanar waveguide structure with a higher direct modulation speed, and can be integrated with flip chip technology. Therefore, the disclosure reduces the signal transmission loss caused by package wiring and reduces the thermal effect caused by the device itself, and significantly improves the high frequency and photoelectric characteristics at high temperature.

Embodiments disclosed herein include dual sided cooling architectures for laser packages. In an embodiment, an electronic package comprises a package substrate, and a laser chip attached to the package substrate. In an embodiment, the laser chip has a first surface and a second surface opposite from the first surface. In an embodiment, an interposer is disposed over the laser chip, where the interposer overhangs an edge of the laser chip. In an embodiment, the electronic package further comprises an interconnect between the interposer and the package substrate.

A photonic crystal surface-emitting laser includes a light emitting module and a driving module. The light emitting module includes a photonic crystal layer, an active light emitting layer on a side of the photonic crystal layer, a first electrode on a side of the active light emitting layer facing away from the photonic crystal layer, and a second electrode partially on the side of the active light emitting layer facing away from the photonic crystal layer. The driving module makes electrical contact with surfaces of the first electrode and the second electrode facing away from the photonic crystal layer. The driving module outputs driving signals to the first electrode and the second electrode to drive the active light emitting layer to generate photons. The photons are incident into the photonic crystal layer to generate a laser light through oscillation on Bragg diffraction. An optical system is also disclosed.