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.

There is provided a Q-switched semiconductor light-emitting element, including a comb electrode that has at least two or more gain regions and two or more absorption regions, the regions including an active layer and being continuous on a semiconductor substrate, separation regions being provided between the gain regions and the absorption regions, the longest region of the gain regions being located on a rear end surface side; and an optical waveguide that staddles the gain regions, the absorption regions, and the separation regions.

A synthesizer includes a first resonator mirror, a second resonator mirror, and a gain medium disposed within a laser resonator cavity defined by the first resonator mirror and the second resonator mirror. The synthesizer includes a saturable absorber operationally coupled to the gain medium and having active control such that the saturable absorber is configured to generate a waveform via an injection locking signal to create a mode locking effect, the waveform having a frequency comb defined by dimensions of the gain medium. The synthesizer also includes a crystal electro-optical modulator disposed within the laser resonator cavity. The waveform passes through the modulator to impinge on a photodiode to output an emission RF waveform. Changing the voltage applied to the modulator changes the index of refraction of the modulator, altering an optical path length of the laser resonator cavity to adjust a frequency of the emission RF waveform.

A semiconductor laser drive circuit includes: an anode electrode divided into at least one gain region and at least one light absorption region; a cathode electrode shared between the gain region and the light absorption region; and a resistance connected to the anode electrode of the light absorption region.

A semiconductor laser including: an optical resonator that has a first compound semiconductor layer containing an n-type impurity, a second compound semiconductor layer containing a p-type impurity, and a light-emitting layer provided between the first compound semiconductor layer and the second compound semiconductor layer; and a pulse injection means that injects excitation energy for a sub-nanosecond duration into the optical resonator, wherein the light-emitting layer has an at least five-period multiple quantum well structure, and the semiconductor laser generates optical pulses having a pulse width shorter than 2.5 times the photon lifetime in the optical resonator.

A semiconductor laser including: an optical resonator that has a first compound semiconductor layer containing an n-type impurity, a second compound semiconductor layer containing a p-type impurity, and a light-emitting layer provided between the first compound semiconductor layer and the second compound semiconductor layer; and a pulse injection means that injects excitation energy for a sub-nanosecond duration into the optical resonator, wherein the optical resonator has a multi-section structure separated into at least one gain region and at least one absorption region, and the semiconductor laser generates optical pulses having a pulse width shorter than 2.5 times the photon lifetime in the optical resonator.

An embodiment relates to a light source module dynamically controlling a phase distribution of light. The light source module includes a semiconductor stack portion. The semiconductor stack portion includes a stacked body including an active layer and a photonic crystal layer causing Γ-point oscillation, and includes a phase synchronization portion and an intensity modulation portion which are arranged in a Y-direction as one resonance direction of the photonic crystal layer. The stacked body in the intensity modulation portion has M (≥2) pixels each arranged in an X-direction and including N.sub.1 (≥2) subpixels. A length of a region including consecutive N.sub.2 (≥2, ≤N.sub.1) subpixels among the N.sub.1 subpixels, defined in the X-direction, is smaller than an emission wavelength of the active layer. The light source module outputs laser light from each M pixel included in the intensity modulation portion in a direction intersecting both X- and Y-directions.

A method (900) includes a gain current (I.sub.GAIN) to an anode of a gain-section diode (D.sub.0) disposed on a shared substrate of a tunable laser (310), delivering a modulation signal to an anode of an Electro-absorption section diode (D.sub.2) disposed on the shared substrate of the tunable laser, and receiving a burst mode signal (330) indicative of a burst-on state or a burst-off state. When the burst mode signal is indicative of the burst-off state, the method includes sinking a sink current (I.sub.SINK) away from the gain current at the anode of the gain-section diode. When the burst mode signal transitions to be indicative of the burst-on state from the burst-off state, the method includes ceasing the sinking of the sink current away from the gain current and delivering an overshoot current (I.sub.OVER) to the anode of the gain-section diode.

A system and method for tuning and infrared source laser in the Mid-IR wavelength range. The system and method comprising, at least, a plurality of individually tunable emitters, each emitter emitting a beam having a unique wavelength, a grating, a mirror positioned after the grating to receive at least one refracted order of light of at least one beam and to redirect the beam back towards the grating, and a micro-electro-mechanical systems device containing a plurality of adjustable micro-mirrors.

An optoelectronic oscillator for generating an optical and/or electric pulse comb, comprising a monolithically integrated passively mode-coupled semiconductor laser and an optical feedback loop which guides a part of the optical radiation of the semiconductor laser and feeds said part back into the semiconductor laser as feedback pulses. Without the influence of the feedback pulses, the semiconductor laser would emit comb-like optical pulses, hereafter referred to as primary pulses, and in the event of an influence, emits comb-like output pulses which have been influenced by the feedback pulses, said output pulses having a lower temporal jitter or less phase noise than the primary pulses. The feedback loop is damped between 27.5 and 37.5 dB, and the time lag of the feedback loop is selected such that each feedback pulse is incident within the temporal half-value width of each subsequent primary pulse.