Abstract:
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 σSE, a saturable absorber (SA) having an absorption cross section (σa) which is less than three times the σSE 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 (ASA) is smaller than a cross-section of a laser mode within a Rayleigh length of the pump (AGM).
Abstract:
An ultrafast mode-locked laser comprising circuitry configured to drive an electro-optic modulator (EOM) in the mode-locked laser with a drive waveform, the drive waveform being a phase-coherent sinusoidal waveform at a frequency equal to a repetition rate of the mode-locked laser, a phase-coherent pulsed waveform at a frequency equal to the repetition rate of the mode-locked laser, or a phase-coherent sinusoidal waveform at a frequency equal to half of the repetition rate of the mode-locked laser.
Abstract:
Laser annealing apparatus includes a plurality of frequency- tripled solid-state lasers, each delivering an output beam of radiation at a wavelength between 340 nm and 360 nm. Each output beam has a beam-quality factor (M2) greater of than 50 in one transverse axis and greater than 20 in another transverse axis. The output beams are combined and formed into a line-beam that is projected on a substrate being annealed. Each output beam contributes to the length of the line-beam.
Abstract:
The present invention uses a laser apparatus capable of selecting a wavelength of light to be outputted from a plurality of wavelengths, including: a branching unit which is formed of a polarizer (804) and is configured to branch an optical path formed in a resonator including a reflecting unit having a plurality of fixed reflecting planes and an output mirror (802), into a plurality of optical paths, thereby forming a common optical path (809) having an end defined by the output mirror (802) and a plurality of optical path branches (810,811) each having an end defined by any one of the reflecting planes (807,808); a laser medium (803) disposed in the common optical path (809); and a selecting unit (805) configured to select, from the plurality of optical path branches (810,811), an optical path branch which corresponds to a wavelength of light to be outputted. The selecting unit (805) may be a Pockels cell which can take in addition the function of a Q-switch.
Abstract:
Apparatus (10) comprising an optical fibre laser (22) having at least two laser cores (23A, 23B) and means (16, 20) arranged to combine laser output from the at least two laser cores at a first end (19) of the optical fibre laser to produce a combined laser output (29) having one or more beat signals.
Abstract:
The invention relates to methods for suppressing or preventing non-linear effects, such as bifurcations of the emitted intensity, in lasers. Also disclosed are laser arrays which are configured so as to be operated without allowing such effects to occur. In order to suppress non-linear effects in the laser emission, the parameters of the laser array are selected such that non-linear effects are prevented from occurring from the start and the laser emits in an inherently stable manner. Alternatively, operation of the laser is dynamically regulated by varying at least one adjustable variable that influences laser emission in accordance with at least one error signal which is based on the extracted pulse energy of the laser emission in such a way that an unstable behavior of the laser emission is prevented or suppressed.
Abstract:
A laser (2) includes a gain medium (10), a switch element (12) and a pulse controller (14). In one embodiment laser light of differing polarisations pass along respective paths and a pulsed laser output is generated via an electro-optical element. In another embodiment light of differing polarisations passes in differing directions through a cylical path. The invention can make use of a prism-shaped polariser having a polarisation selection face and two further faces. Yet further initial pulses can be controlled to reduce energy for example by progressively increasing the period or amplitude of successive pulses. As a result an efficient and high power laser apparatus is realised.