A laser adjustment method includes a first adjustment step and a second adjustment step. In the first adjustment step, using a light detector detecting a second harmonic light, optical intensity and wavelength of the second harmonic light is detected and a first temperature adjuster is adjusted to adjust temperatures of a Nd:YVO.sub.4 crystal and a KTP crystal such that the detected wavelength of the second harmonic light approaches a desired wavelength and such that the optical intensity of the second harmonic light reaches at least a predetermined value. In the second adjustment step, after the first adjustment step, a temperature of an etalon is adjusted by a second temperature adjuster such that the detected wavelength of the second harmonic light approaches the desired wavelength and such that the optical intensity of the second harmonic light reaches at least a predetermined value.

A gain mirror is created for use as an optical amplifier in a solid state ring laser rotation sensor. Such a ring laser includes at least three mirrors for reflecting counter propagating laser beams around a closed loop optical path, wherein at least one of the mirrors is a gain mirror. The gain mirror is formed by applying a thin film of silica, a few half wavelengths thick and doped with Nd isotopes, onto a very high reflectivity mirror and then using a laser diode to pump it with intense light to form a population inversion in Nd.sup.3+ ions. An assembly consisting of this gain mirror and a pump laser diode can be used as an optical amplifier in a solid state ring laser to generate the two counter propagating laser light beams needed to measure rotation.

A technique which is suitable in joining an end surface of a laser medium to a transparent heat sink for maintaining thermal resistance therebetween low and avoiding large thermal stress from acting on the laser medium is to be provided. An end coat is provided on the end surface of the laser medium, a same-material layer constituted of a same material as the heat sink is provided on a surface of the end coat, a surface of the same-material layer and an end surface of the heat sink are activated in a substantially vacuum environment, and those activated surfaces are bonded in the substantially vacuum environment. A laser apparatus having low thermal resistance between the laser medium and the heat sink and high transparency at a joint interface therebetween, and no large thermal stress acting on the laser medium is thereby obtained.

A laser system comprising a gain medium configured to amplify incident electromagnetic radiation and a nonlinear optical element configured to convert electromagnetic radiation amplified by the gain medium to a shorter wavelength. The laser system is configured to introduce mode competition and nonlinear effects such that the nonlinear optical element produces output electromagnetic radiation having a frequency spectrum comprising a first peak formed of a first group of frequencies and a second peak formed of a second group of frequencies. A trough separates the first and second peaks. The first and second peaks are the only dominant peaks in the frequency spectrum. The output electromagnetic radiation has a coherence curve comprising a contrast ratio of less than about 0.1 at an optical path difference that is within the inclusive range of about 1.5 mm to about 2.5 mm.

A laser system is described, the laser system comprising: an optical cavity defined by at least first and second at least partially reflecting elements; and a gain system. The gain system comprising at least first and second gain media located within the optical cavity. The first and second gain media are configured to generate optical radiation of at least first and second wavelength ranges in response to pumping energy.

Systems and methods described herein may include a first semiconductor layer with a first lattice constant, a rare earth pnictide buffer epitaxially grown over the first semiconductor, wherein a first region of the rare earth pnictide buffer adjacent to the first semiconductor has a net strain that is less than 1%, a second semiconductor layer epitaxially grown over the rare earth pnictide buffer, wherein a second region of the rare earth pnictide buffer adjacent to the second semiconductor has a net strain that is a desired strain, and wherein the rare earth pnictide buffer may comprise one or more rare earth elements and one or more Group V elements. In some examples, the desired strain is approximately zero.

Passively Q-switched lasers and short wave infrared (SWIR) electro-optical systems including such lasers. A passively Q-switched laser may include a gain medium (GM) having a stimulated emission cross section σ.sub.SE, a saturable absorber (SA) having an absorption cross section (σ.sub.a) which is less than three times the σ.sub.SE of the GM, and an optical resonator within which the GM and the SA are positioned, the optical resonator comprising a high reflectivity mirror and an output coupler, wherein at least one of the high reflectivity mirror and the output coupler comprises a curved mirror, directing light within the optical resonator such that an effective cross-section of a laser mode within the SA (A.sub.SA) is smaller than a cross-section of a laser mode within a Rayleigh length of the pump (A.sub.GM).

Systems, devices and methods are described including providing infrared (IR) laser radiation to a Digital Micromirror Device (DMD) array and using the DMD array to spatially modulate the IR laser radiation. The spatially modulated IR laser radiation may then be projected to form a voxel array where each voxel of the array represents to a volume of air wherein the IR laser radiation has been focused sufficiently to cause air to ionize. The voxel array may then be spatially rotated.

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.

The invention discloses a preparation method and device of active microcrystalline fiber, place the prefabricated rod in the drawing furnace for wire drawing, the drawn fiber is induced by magnetic field in uncoated state and combined with laser treatment technology, the laser beam is focused on the fiber and recrystallized after laser treatment to obtain active microcrystalline fiber. Appropriate laser processing power directly affects the silicate glass fiber in the crystal structure, type, degree of crystallinity, grain size, content, and how much residual phase of glass. Induced by external magnetic field, the thermodynamics and dynamics of crystallization process are changed, make the crystal size distribution is better and uniform, reduce the phenomenon of condensation and makes the grain size is smaller.