A driver circuit may include an optical emitter, a capacitive element, and an inductive element. The driver circuit may include a first switch that, in a closed state, is to cause charging of the inductive element, and when transitioning from the closed state to an open state is to cause discharging of the inductive element to charge the capacitive element. The driver circuit may include a second switch that in a closed state is to cause discharging of the capacitive element to provide an electrical pulse to the optical emitter. The driver circuit may include a signal generator configured to generate a first signal for controlling the open state and the closed state of the first switch, and a pulse shortening element configured to shorten a pulse width of the first signal to generate a second signal for controlling the open state and the closed state of the second switch.

A light emitting device according to an embodiment of the present disclosure includes: a substrate; a first contact layer; a buffer layer in which at least any of a carrier concentration, a material composition, and a composition ratio is different from that of the first contact layer; and a semiconductor stacked body. The substrate has a first surface and a second surface that are opposed to each other. The first contact layer is stacked on the first surface of the substrate. The buffer layer is stacked on the first contact layer. The semiconductor stacked body is stacked above the first surface of the substrate with the first contact layer and the buffer layer interposed in between. The semiconductor stacked body has a light emitting region configured to emit laser light.

In some implementations, a vertical cavity surface emitting laser (VCSEL) package may include a substrate. The VCSEL package may include a VCSEL disposed on a surface of the substrate. The VCSEL package may include a VCSEL driver disposed on the surface of the substrate. The VCSEL package may include an embedded capacitor electrically connected to the VCSEL and the VCSEL driver. The embedded capacitor may be formed from a subset of layers of the substrate. The capacitor may be associated with a first capacitance that is different from a second capacitance of at least one other capacitor associated with the substrate.

In some implementations, a vertical cavity surface emitting laser (VCSEL) package may include a substrate. The VCSEL package may include a VCSEL disposed on a surface of the substrate. The VCSEL package may include a VCSEL driver disposed on the surface of the substrate. The VCSEL package may include an embedded capacitor electrically connected to the VCSEL and the VCSEL driver. The embedded capacitor may be formed from a subset of layers of the substrate. The capacitor may be associated with a first capacitance that is different from a second capacitance of at least one other capacitor associated with the substrate.

The disclosure relates in some aspects to providing miniature power-efficient agile photonic generators of microwave waveforms. Illustrative examples use chip lasers integrated in close thermal proximity with one another to provide a miniature microwave arbitrary waveform generator (AWG). Due to the small size of the lasers and the close integration, common ambient fluctuations from the environment or other sources can be efficiently reduced, yielding improved spectral purity of generated radio-frequency (RF) signals. Tight physical integration also permits a small device footprint with minimal acceleration sensitivity. The lasers may be locked to cavities or other resonators to allow efficient decoupling of the frequency and amplitude modulation of the lasers to provide flexibility to the waveform generator. Exemplary devices described herein can produce frequency chirped signals for radar applications. The frequency chirp may be linear and/or nonlinear. Tuning methods are also described herein.

A transmitter unit for emitting radiation into the surrounding area, including at least one semiconductor laser, which has at least one first emitter possessing a first section and a second section; and at least one control unit for controlling the semiconductor laser. The control unit is configured to apply a first supply variable to the first section of the at least one emitter, and to apply a second supply variable differing from the first supply variable, to the second section of the at least one emitter.

A method of producing a laser diode bar includes producing a plurality of emitters arranged side by side, emitters each including a semiconductor layer sequence having an active layer that generates laser radiation, a p-contact on a first main surface of the laser diode bar and an n-contact on a second main surface of the laser diode bar opposite the first main surface, testing at least one optical and/or electrical property of the emitters, wherein emitters in which the optical and/or electrical property lies within a predetermined setpoint range are assigned to a group of first emitters, and emitters in which the at least one optical and/or electrical property lies outside the predetermined setpoint range are assigned to a group of second emitters, and electrically contacting first emitters, wherein second emitters are not electrically contacted so that they are not supplied with current during operation of the laser diode bar.

This optical semiconductor element includes: a substrate; a first ridge formed on the substrate and having a first first-conductivity-type cladding layer, a first core layer, a first second-conductivity-type cladding layer, and a first contact layer in this order from a lower side, with first ridge grooves provided on both lateral sides of the first ridge; and a first electrode formed in contact with the first contact layer, on the first ridge, without spreading to the first ridge grooves, the first electrode including a first solder layer.

A method for manufacturing a light emitting element according to the present disclosure is a method for manufacturing a light emitting element which includes a stacked structure 20 in which a first compound semiconductor layer 21, an active layer 23, and a second compound semiconductor layer 22 are stacked, a first light reflecting layer 41, and a second light reflecting layer 42 having a flat shape, and in which a base surface 90 positioned on a first surface side of the first compound semiconductor layer 21 has a protrusion 91 protruding in a direction away from the active layer 23, and a cross-sectional shape of the protrusion 91 includes a smooth curve, the method including: forming a first sacrificial layer 81 on the base surface on which the protrusion 91 is to be formed; forming a second sacrificial layer 82 on the entire surface; and performing etching back from the base surface 91 inward by using the second sacrificial layer 82 and the first sacrificial layer 81 as etching masks.

To provide a light-emitting apparatus capable of shaping light from a plurality of light-emitting elements into light with a plurality of shapes and a manufacturing method thereof. A light-emitting apparatus according to the present disclosure, including: a substrate; a plurality of light-emitting elements which are provided on a side of a first surface of the substrate; and a plurality of first lenses which are provided on a side of a second surface of the substrate and on which light emitted from the plurality of light-emitting elements is incident, wherein the plurality of first lenses include at least two types of lenses among a concave lens, a convex lens, and a flat lens.