An optical coherence analysis system uses a laser swept source that is constrained to operate in a stable mode locked condition by modulating a drive current to the semiconductor optical amplifier as function of wavelength or synchronously with the drive voltage of the laser's tunable element based on stability map for the laser.

A semiconductor-laser-device assembly includes a mode-locked semiconductor-laser-element assembly including a mode-locked semiconductor laser element, and a dispersion compensation optical system, on which laser light emitted from the mode-locked semiconductor laser element is incident and from which the laser light is emitted; and a semiconductor optical amplifier having a layered structure body including a group III-V nitride-based semiconductor layer, the semiconductor optical amplifier configured to amplify the laser light emitted from the mode-locked semiconductor-laser-element assembly.

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.

Provided is an optical semiconductor element including: a stacked structure body 20 formed of a first compound semiconductor layer 21, a third compound semiconductor layer (active layer) 23, and a second compound semiconductor layer 22. A fundamental mode waveguide region 40 with a waveguide width W.sub.1, a free propagation region 50 with a width larger than W.sub.1, and a light emitting region 60 having a tapered shape (flared shape) with a width increasing toward a light emitting end surface 25 are arranged in sequence.

Disclosed is a semiconductor laser device assembly including a semiconductor laser device; and a dispersion compensation optical system, where a laser light exited from the semiconductor laser device is incident and exits to control a group velocity dispersion value of the laser light exited from the semiconductor laser device per wavelength.

In an embodiment, a laser apparatus comprises a semiconductor laser, e.g., of the VECSEL type, for generating pulsed laser radiation having a pulse duration in the femtosecond range or shorter and having a pulse repetition rate of at least 100 MHz; a selector for selecting groups of pulses from the laser radiation, each pulse group comprising a plurality of pulses at the pulse repetition rate, wherein the pulse groups are time-displaced by at least 500 ns; a scanner device for scanning a focal point of the laser radiation; a controller for controlling the scanner device based on a control program including instructions that, when executed by the controller, bring about the creation of a LIOB-based photodisruption for each pulse group in a target material, e.g. human eye tissue.

A beam combining device and method for a Bragg grating external-cavity laser module has a plurality of side by side light-emitting modules that use a Bragg grating to perform wavelength locking. Output light of the modules is incident to a beam combining element after passing through a focusing optical element for beam combining, and light subjected to beam combining is reflected partially and transmitted partially under the effect of a light splitting element. A part is incident into a dispersion element at a diffraction angle of the element. Parallel light is formed under the effect of a conversion optical element. Spots of the light beams of corresponding wavelengths of the light-emitting modules are formed on an image acquisition mechanism. Whether the wavelengths of the corresponding light-emitting modules are locked is determined by whether there is a deviation between preset spots and spots formed by the module on the acquisition mechanism.

Disclosed is a self-locked laser system, including: a semiconductor substrate; a laser diode including a first semiconductor part disposed on the semiconductor substrate, and which generates an optical signal; an unidirectional Whispery Gallery Mode (WGM) resonator including a second semiconductor part disposed on the semiconductor substrate; and a structure emitting an optical signal self-locked by the optical signal of the laser diode, in which the laser diode and the resonator are optically coupled on the semiconductor substrate.

A supercontinuum light source can include a seed laser arranged to provide seed pulses with a pulse frequency F.sub.seed; a pulse frequency multiplier (PFM) arranged to multiply the seed pulses by converting pulses having the pulse frequency F.sub.seed to pump pulses with a pulse frequency F.sub.pump, where F.sub.pump is larger than F.sub.seed; and a non-linear element arranged to receive said pump pulses and convert said pump pulses to pulses of supercontinuum light. The PFM can further include a splitter for splitting pulses into first and second sub beams each having the same pulse frequency, where the PFM is configured such that the sub beams experience different delays; and a combiner for combining said first and second sub beams into a beam having the pulse frequency that is greater than said same pulse frequency. The splitter can have an uneven splitter ratio.

A wireless communication device includes a quantum cascade laser (QCL) configured to generate a terahertz (THz) or microwave carrier signal. The QCL includes a laser waveguide, a laser optical gain medium incorporated in the laser waveguide, and at least one electrode. An antenna may be integrated with the electrode. The device may be a transmitter, the electrode configured to receive an input baseband signal, the QCL configured to couple the THz or microwave carrier signal and the input baseband signal into a THz or microwave communication signal, and the antenna configured to transmit the THz or microwave communication signal. The device may be a receiver, the antenna configured to receive a THz or microwave communication signal, and the QCL configured to de-couple the THz or microwave communication signal from the THz or microwave carrier signal into an output baseband signal.