The invention relates to an external cavity tunable laser with dual beam outputs. The first laser cavity of the tunable laser comprises a first laser cavity mirror, a laser gain medium, an intracavity collimating lens, an active optical phase modulator, a tunable acousto-optic filter, a tunable Fabry-Perot tunable filter, a second reflection mirror all disposed inside a laser cavity sequentially, and a laser driver and control system. The laser cavity beam reflected by the first laser cavity mirror enters the tunable acousto-optic filter to generate a zeroth order diffracted beam as the first laser output beam. The laser cavity beam reflected by the second laser cavity mirror enters the tunable acousto-optic filter to generate a zeroth order diffracted beam as the second laser output beam. The tunable laser further comprises a wavelength locker outside the laser cavity. The second laser cavity of the tunable laser has a Fabry-Perot etalon disposed in the first laser cavity to further compress the spectrum width of the laser output beams. The invention is compact with high performance without mechanical moving parts, stable laser output, low cost for volume production and installation.

A tunable external cavity laser with dual gain chips, including: a polarization beam splitter having a beam splitting surface arranged at an angle of 45? with respect to a first direction and a second direction perpendicular to the first direction; a first gain chip arranged in the first direction; a second gain chip arranged in the second direction; a feedback cavity arranged in the first direction, wherein the feedback cavity and the first gain chip are respectively arranged on two opposite sides of the polarization beam splitter, and the feedback cavity includes at least one independent Fabry-Perot etalon, at least one air gap Fabry-Perot cavity and a mirror that are arranged in the first direction. The polarization beam splitter and the two gain chips cooperate to share the feedback cavity, so that a wavelength and a phase may be adjusted, and a larger tuning range may be obtained.

A laser oscillator includes: an external resonator configured to include laser media to emit laser beams having different wavelengths; and a partially reflective mirror to transmit part of the laser beams and reflect and return a remainder toward the laser media. The external resonator includes therein: a diffraction grating to perform wavelength coupling on the laser beams having different wavelengths emitted from the laser media so as to superimpose the laser beams into one laser beam and to emit, to the partially reflective mirror, the one laser beam; and a prism that is placed between the laser media and the diffraction grating and that superimposes the laser beams into one laser beam on the diffraction grating, the prism including two surfaces forming an apex angle, one of the two surfaces being an incident surface and another of the two surfaces being an exit surface.

A system, apparatus, and method for multiple wavelength Raman interrogation laser generation and Raman spectra acquisition. An intracavity laser tuning subsystem is integrated into the laser cavity. The tuning subsystem allows switching between at least two laser output frequencies in a manner effective for good identification and separation of Raman spectra from non-Raman spectra, including auto-fluorescence from the sample and background. The tuning subsystem can be implemented in different ways in the cavity. It does not require material alteration of the line-narrowing components. Also, processing of acquired raw signal from the multiple wavelength interrogation can further assist effective Raman spectra identification and separation.

A narrow band laser apparatus may include: a laser resonator; a pair of discharge electrodes; a power supply; a first wavelength measurement device configured to output a first measurement result; a second wavelength measurement device configured to output a second measurement result; and a control unit. The control unit calibrates the first measurement result, based on a difference between the second measurement result derived when the control unit controls the power supply to apply a pulsed voltage to the pair of discharge electrodes with a first repetition frequency and the second measurement result derived when the control unit controls the power supply to apply the pulsed voltage to the pair of discharge electrodes with a second repetition frequency, the second repetition frequency being higher than the first repetition frequency.

A laser apparatus generating frequency converted light. Embodiments of the laser apparatus described herein apply a cascade of nonlinear frequency mixer for sum frequency generation (SFG) or difference frequency generation (DFG) between two frequency components of a spectrally combined laser beam with at least two spectral components originating from two respective laser sources, SFG of two frequency components beams offers up to a factor of four amplification of output power over SHG of a single laser beam.

A variable-wavelength light source is provided with a first laser medium, a first optical resonator constituted of a total reflection mirror and a half-mirror, a second laser medium, a second optical resonator constituted of a total reflection mirror and the half-mirror, a first filter having a pair of first mirrors configured to cause first light and second light to be transmitted and reflected selectively, a second filter having a pair of second mirrors configured to cause the first light and the second light to be transmitted and reflected selectively, a first drive mechanism configured to operate the first mirror and the second mirror in conjunction with each other, and a second drive mechanism configured to operate the second mirror.