Abstract:
In a laser device and a photoacoustic measurement device including the laser device, the intensity of light at each wavelength made independently controllable. The laser device includes a laser medium which has oscillation wavelengths at a first wavelength and a second wavelength with higher light emission efficiency than at the first wavelength, an excitation section, a first resonator, a second resonator, a Q-value change unit, and a control section. The control section oscillates light having the first wavelength through Q switching when a first delay time has elapsed after the excitation of the laser medium has been started in a case where the oscillation wavelength is the first wavelength, and oscillates light having the second wavelength through Q switching when a second delay time has elapsed after the excitation of the laser medium has been started in a case where the oscillation wavelength is the second wavelength.
Abstract:
A laser beam combining and power scaling device and method. A first highly reflective mirror residing perpendicular to the first optical axis reflecting radiation emitted from the first laser head. A first Q-switch in alignment with the first optical axis interposed between the first highly reflective mirror and the first laser head. A second highly reflective mirror residing perpendicular to the second optical axis reflecting radiation emitted from the second laser head. The second Q-switch in alignment with the second optical axis is interposed between the second highly reflective mirror and the first laser head. A third optical axis is coincident with the first optical axis. A third highly reflective mirror residing perpendicular to the third optical axis in alignment therewith. The third optical axis may include a third diode pumped laser head and Q-switch. A beam splitter resides at the intersection of the axes.
Abstract:
A laser beam combining and power scaling device and method. A first highly reflective mirror residing perpendicular to the first optical axis reflecting radiation emitted from the first laser head. A first Q-switch in alignment with the first optical axis interposed between the first highly reflective mirror and the first laser head. A second highly reflective mirror residing perpendicular to the second optical axis reflecting radiation emitted from the second laser head. The second Q-switch in alignment with the second optical axis is interposed between the second highly reflective mirror and the first laser head. A third optical axis is coincident with the first optical axis. A third highly reflective mirror residing perpendicular to the third optical axis in alignment therewith. The third optical axis may include a third diode pumped laser head and Q-switch. A beam splitter resides at the intersection of the axes.
Abstract:
A high-power diode end-pumped solid-state UV laser comprises high-power fiber-coupled end pumping laser diodes, a specially designed fundamental laser cavity and multiple high-power high-efficiency harmonic generations. Nonuniform fundamental laser cavity has to be used, i.e. the beam size of the fundamental laser cannot be uniform in the fundamental cavity. Thermal transfer inside the laser crystal and harmonic crystal has to be specially and carefully treated, and special crystal mounts were designed to optimize the thermal contact and maximize the heat transfer. In addition, harmonic crystal mounts were specially designed to minimize the loss and protect the hydroscopic crystals.
Abstract:
A laser beam combining and power scaling device and method. A first highly reflective mirror residing perpendicular to the first optical axis reflecting radiation emitted from the first laser head. A first Q-switch in alignment with the first optical axis interposed between the first highly reflective mirror and the first laser head. A second highly reflective mirror residing perpendicular to the second optical axis reflecting radiation emitted from the second laser head. The second Q-switch in alignment with the second optical axis is interposed between the second highly reflective mirror and the first laser head. A third optical axis is coincident with the first optical axis. A third highly reflective mirror residing perpendicular to the third optical axis in alignment therewith. The third optical axis may include a third diode pumped laser head and Q-switch. A beam splitter resides at the intersection of the axes.
Abstract:
A high-power diode end-pumped solid-state UV laser comprises high-power fiber-coupled end pumping laser diodes, a specially designed fundamental laser cavity and multiple high-power high-efficiency harmonic generations. Nonuniform fundamental laser cavity has to be used, i.e. the beam size of the fundamental laser cannot be uniform in the fundamental cavity. Thermal transfer inside the laser crystal and harmonic crystal has to be specially and carefully treated, and special crystal mounts were designed to optimize the thermal contact and maximize the heat transfer. In addition, harmonic crystal mounts were specially designed to minimize the loss and protect the hydroscopic crystals.
Abstract:
A novel Q-switch device enables significant quality and value improvement for a Q-switched laser system by achieving a significant reduction of mode-beating noise during the pulsed output. The origin of mode-beating noise in a Q-switched laser is a result of high gain availability and amplification of competing standing-waves in formation, whose optical frequency is a product of natural selection via spatial hole burning in the gain medium. The novel Q-switch device employs an active, electro-optics or acousto-optics, Q-switch in combination with a saturable absorber device, to provide an optimized soft opening of the optical path and a controlled timing of a Q-switched laser. This novel combination offers larger modulation loss than otherwise possible with the active modulator alone, and it allows for higher gain build-up and energy extraction efficiency. Specifically, it will enable a low-voltage modulator ( 10) and Q-switched operation at high repetition rate (>10 kHz). The combination is devised to slow down the signal build-up and to sweep the fundamental longitudinal mode frequency at least within the free spectral range of the resonator, such that it varies adiabatically during the Q-switched pulse formation. A laser geometry amenable to high gain and high power is proposed for use in conjunction with the proposed novel Q-switch device. The invention will enable the deployment of cost-effective Q-switched lasers operating in both single-longitudinal and single-transverse (TEM00) mode.
Abstract:
Two laser media are disposed at equal intervals between a first flat mirror, which is a resonator mirror comprising a resonator, and a second flat mirror for separating laser light that transmits second-harmonic laser light and reflects fundamental laser light toward a laser light incident plane; and a dielectric multilayer film is formed on the second flat mirror for separating the laser light. A third flat mirror, which is a resonator mirror, is disposed so as to face a direction 90° to the incident direction of the fundamental laser light in the second flat mirror. A first lens, a nonlinear optical crystal for converting fundamental laser light into a second-harmonic laser light, and a second lens are disposed in sequence in a single row at intervals that are equal to the focal distances f of the first and second lenses between the second and third flat mirrors. Space for accommodating a nonlinear optical crystal and a mirror for separating second-harmonic laser light can thereby be secured while maintaining stabilized resonance conditions, and the output of the solid-state laser generator can be increased.
Abstract:
A Q-switch modulator for a high power laser having a randomly polarized output beam and large divergence angle employs a cascaded arrangement of longitudinal mode acousto-optic modulators, each of which has a Raman Nath or near Raman Nath interaction length. The modulators are optically cascaded such that the distance the randomly polarized laser beam travels through the modulators is effectively confined to the sum of the non coherent interaction lengths thereof. Due to the substantial power level of the laser output, there is heating of the bulk material, which usually results in a shift in the Bragg angle. This has minimal if any effect on the shorter interaction length of the Q-switch modulator of the invention. Also, heating of the bulk material is countered by the incorporation of cooling fluid channels in a heat sink support block coupled in thermal communication with the bulk material. The heat sink support structure is configured to be effectively mechanically floating with respect to a support housing for the Q-switch.
Abstract:
A laser with high average power, high repetition rate, ultra-short pulsewidth, and excellent beam quality is described. This is achieved by the use of high power diodes used to uniformly pump an improved Nd:YAlO.sub.3 crystal, resulting in a beam with excellent quality. In addition, a beta-barium borate (BBO) crystal, used in conjunction with drift step recovery diodes (DSRDs), forms a high speed optical switch which can be used to cavity dump the laser.