Apparatus and methods for forming fine scale structures (4, 4′, 4″, 5, 6, 7, 8) in the surface of a dielectric substrate (3) to two or more depths are disclosed. In an example, the apparatus comprises a first solid state laser (12) arranged to provide a first pulsed laser beam (13), a first mask (16) having a pattern for defining a first set of structures (4, 6, 7, 8) at a first depth, a projection lens (17) for forming a reduced size image of said pattern on the surface (3) of the substrate and a beam scanner arranged to scan said first pulsed laser beam (13) in a two-dimensional raster scan relative to the first pattern to form a first set of structures (4, 6, 7, 5) at a first depth in the substrate, wherein the first or a further solid state laser is arranged to form a second set of structures (8) at a second depth in the substrate (3).

The invention relates to a microstructured optical fiber for generating incoherent supercontinuum light upon feeding of pump light. The microstructured optical fiber has a first section and a second section. A cross-section through the second section perpendicularly to a longitudinal axis of the fiber has a second relative size of microstructure elements and preferably a second pitch that is smaller than a blue edge pitch for the second relative size of microstructure elements. The invention also relates to an incoherent supercontinuum source comprising a microstructured optical fiber according to the invention.

A laser system comprising an RE:XAB gain medium within a resonator cavity. X is selected from Ca, Lu, Yb, Nd, Sm, Eu, Gd, Ga, Tb, Dy, Ho, Er, and RE is selected from Lu, Y, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Pr, Tm, Cr, Ho. The system further comprises a pumping source having optical output directed towards the gain medium. A laser controller operates the pumping source. The system further comprises a heat spreader, the heat spreader in thermal communication with the gain medium through a surface wherein the pump source has optical output incident.

A fiber optic sensor interrogation system with inbuilt passive power limiting capability based on stimulated Brillouin scattering that provides improved safety performance for use in explosive atmospheres.

In one aspect, the present disclosure describes a fiber laser system for the generation and delivery of femtosecond (fs) pulses in multiple wavelength ranges. For improved versatility in multi-photon microscopy, an example of a dual wavelength fiber system based on Nd fiber source providing gain at 920 and 1060 nm is described. An example of a three-wavelength system is included providing outputs at 780 nm, 940 nm, and 1050 nm. The systems include dispersion compensation so that high quality fs pulses are provided for applications in microscopy, for example in multiphoton microscope (MPM) systems.

Disclosed is a system and method for remote sensing, surface profiling, object identification, and aiming based on two-photon population inversion and subsequent photon backscattering enhanced by superradiance using two co-propagating pump waves. The present disclosure enables efficient and highly-directional photon backscattering by generating the pump waves in properly pulsed time-frequency modes, proper spatial modes, with proper group-velocity difference in air. The pump waves are relatively delayed in a tunable pulse delay device and launched to free space along a desirable direction using a laser-pointing device. When the pump waves overlap in air, signal photons will be created through two-photon driven superradiant backscattering if target gas molecules are present. The backscattered signal photons propagate back, picked using optical filters, and detected. By scanning the relative delay and the launching direction while the signal photons are detected, three-dimensional information of target objects is acquired remotely.

In one embodiment, a lidar system includes a Q-switched laser configured to emit pulses of light, where the Q-switched laser includes a gain medium and a Q-switch. The lidar system further includes a scanner configured to scan the emitted pulses of light across a field of regard and a receiver configured to detect at least a portion of the scanned pulses of light scattered by a target located a distance from the lidar system. The lidar system also includes a processor configured to determine the distance from the lidar system to the target based at least in part on a round-trip time of flight for an emitted pulse of light to travel from the lidar system to the target and back to the lidar system.

Generator for wholly optical tunable broadband linearly chirped signal comprising a mode-locked laser, a first optical coupler, a first optical filter, a first dispersion module, a second optical filter, a second dispersion module, a tunable time delay module, a second optical coupler, an optical amplifier, and a photodetector. The generator of the present invention employs just one mode-locked laser as a light source, thus preventing instability of the generated signal resulting from independent unrelated lasers. By making use of the principle of wavelength-time mapping and by means of adjusting the center wavelength and the filter bandwidth of the first optical filter and the second optical filter, easy and flexible tuning of the center frequency and sweep bandwidth of the generated linearly chirped signal is realized. The present invention possesses a big advantage on the aspect of generating a broadband linearly chirped signal over other solutions.

An apparatus for emitting pulsed electromagnetic laser radiation includes a laser gain element; an optical arrangement defining a laser resonator and arranged to re-direct radiation emitted by the gain element along a beam path back onto the gain element, the optical arrangement comprising an output coupler configured to couple a portion of the radiation in the laser resonator out of the laser resonator; and, a pump arrangement configured to pump the laser gain element. The optical arrangement includes a mode locker placed in the laser resonator in the beam path, and a birefringent element placed in the laser resonator in the beam path.

A method for generating femtosecond vortex beams with high spatial intensity contrast, where a noncollinearly pumped HG beam femtosecond laser generates femtosecond HG beam and a cylindrical lens mode converter converts the femtosecond HG beam to femtosecond LG vortex beam. The HG beam femtosecond laser comprises a pump source, a gain medium, a saturable absorption mirror as mode-locker, and an output coupler with a noncollinear angle between the laser beam and the pump beam in the gain medium, which enables the laser to generate pure, order-tunable femtosecond HG beams. Femtosecond vortex beams obtained after the cylindrical lens converter have high-intensity-contrast, and are topological charge-tunable.