Apparatus for providing optical radiation (1), which apparatus comprises a laser diode (2), a pulse generator (9), and a modulator (5), wherein: the pulse generator (9) is configured to emit picosecond pulses; the modulator (5) is configured to emit nanosecond pulses; the laser diode (2) has a first terminal (6) and a second terminal (7); the pulse generator (9) is connected to the first terminal (6); and the modulator (5) is configured to bias the laser diode (2) below a lasing threshold (8) of the laser diode (2), and the apparatus being characterized in that: the modulator (5) is connected to the second terminal (7); the pulse generator (9) comprises a semiconductor junction (32) connected to a differentiator (4); the semiconductor junction (32) is such that electric current flowing through the semiconductor junction (32) can be turned off more quickly than it can be turned on; and the differentiator (4) is such that a step change that occurs when the electric current flowing through the semiconductor junction (32) is turned off is converted to an electrical pulse, thereby gain switching the laser diode (2) such that it emits an optical pulse (10) having an optical pulse width (11) less than 10 ns.

A compact diode laser achieves high-power, short duration output pulses by separating the lasing action from the pulse-generating mechanism. A diode seed source is configured for gain-switching via a variable RF source. A time lens element includes an intensity modulation device, a phase modulation device, and a pulse compressor. The intensity modulation device carves shorter pulses from the long gain-switched seed pulses, the phase modulation device adds chirp, and the pulse compressor compensates for the chirp while producing high-power short-duration output pulses.

In one embodiment, a laser system includes a seed laser diode configured to produce a free-space seed-laser beam and a seed-laser focusing lens configured to focus the seed-laser beam. The laser system also includes a semiconductor optical amplifier (SOA) that includes a front facet, a back facet, and a waveguide extending from the front facet to the back facet. The SOA is configured to: receive, at the front facet, light from the focused seed-laser beam; amplify the received light as the received light propagates along the SOA waveguide from the front facet to the back facet; and emit, from the back facet, an amplified free-space beam that includes the amplified received light. The laser system further includes a mounting platform, where one or more of the seed laser diode, the seed-laser focusing lens, and the SOA are mechanically attached to the mounting platform.

The disclosure relates in some aspects to a two-point locking system for stabilizing a frequency comb oscillator using at least two optical transitions of the same atomic/molecular sample. In an example, an optical reference sample is provided that is characterized by two or more optical transitions. A coherent light source provides polychromatic coherent light (such as an optical frequency comb). The beams of light, occupying the same spatial mode volume or separated in space, and having frequencies in the vicinity of the optical transitions of the reference sample, interrogate the resonances of the reference sample. Interrogation signals obtained using phase/frequency/amplitude spectroscopy or other spectroscopy techniques are then used to stabilize the frequency harmonics of the light. If the harmonics belong to the same coherent frequency comb, the entire comb becomes stabilized using this procedure. In an illustrative example, a stable atomic optical clock is provided using these techniques.

A pulsed light generation device, includes: a first optical fiber through which first pulsed light and second pulsed light, having an intensity that decreases while an intensity of the first pulsed light increases, and increases while the intensity of the first pulsed light decreases, having been multiplexed and entered therein, are propagated; and a second optical fiber at which the first pulsed light, having exited the first optical fiber and entered therein, is amplified while being propagated therein, wherein: at the first optical fiber, phase modulation occurs in the first pulsed light due to cross phase modulation caused by the second pulsed light; and self-phase modulation occurring in the first pulsed light at the second optical fiber is diminished by the phase modulation having occurred at the first optical fiber.

Provided is a technology for suppressing variations in the waveform of a light emission pulse caused by various factors in a light-emitting device. A light-emitting device is provided with: a light source 101 in which relaxation oscillation occurs immediately after energization; a light source drive circuit 104 which includes a differentiation circuit 102 having a resistor and a capacitor connected in parallel, and in which a switching element 103 for voltage application is connected in series with the differentiation circuit; a power supply circuit 105; a light-reception element 107 which detects pulsed light emitted from the light source 101; and a voltage control unit 109 which controls an output voltage from the power supply circuit 105 in correspondence with the waveform of the detected pulsed light.

A device comprising a master clock configured to produce a pulse sequence having a wideband light signal of approximately 800 nanometers or red visible wavelength of a predetermined amplitude. The device comprises X laser amplifiers along a common optical path each amplifier being triggered by a burst of X pulses with high-peak power and high-average power. The X laser amplifiers receive the pulse sequence of the master clock and sequentially amplifying the pulse sequence wherein a last laser amplifier of the X laser amplifiers produces an amplified pulse sequence. A compressor is configured to compress the amplified pulse sequence to produce a laser signal having a sequence of directed energy (DE) pulses each DE pulse having a pulse width in a femtosecond range to induce when striking a solid surface of a target object transient electric fields in a microwave frequency range. A system and method are also provided.

This disclosed subject matter allows short pulses with high peak powers to be obtained from seed pulses generated by a gain-switched diode. The gain-switched diode provides a highly stable source for optical systems such as nonlinear microscopy. The disclosed system preserves the ability to generate pulses at arbitrary repetition rates, or even pulses on demand, which can help reduce sample damage in microscopy experiments or control deliberate damage in material processing.

The present invention is related to laser technology which enables efficient, passive, coherent beam combination from distributed gain sources. The present invention includes a novel architecture which coherently combines the power from multiple sources, and which adds considerable flexibility to laser gain materials for many applications. The novel architecture of the present invention combines two techniques: 1) beam splitting and combination; and 2) phase-locking (i.e., maintaining a common phase relationship between multiple beams), using reflective gratings. Thus, the present invention addresses important limitations in laser technology: efficiency, power scaling and wavelength selectivity.

In one embodiment, a laser system includes a seed laser diode configured to produce a free-space seed-laser beam. The laser system also includes a pump laser diode configured to produce a free-space pump-laser beam. The laser system further includes an optical-beam combiner configured to combine the seed-laser and pump-laser beams into a combined free-space beam and a focusing lens configured to focus the combined beam. The laser system also includes an optical gain fiber that includes an input end configured to receive the focused beam. The laser system also includes a mounting platform, where one or more of the optical-beam combiner, the focusing lens, and the input end of the gain fiber are mechanically attached to the platform.