Search

We report theoretical results on the wavelength stability of a multisection master-oscillator power-amplifier emitting at 1064 nm. We use a traveling wave equation model to calculate the optical output power and spectral maps versus the currents injected into the different sections of the device. The numerical model explains quantitatively the experimental findings, particularly the collapse of the power if the current injected into a control section adjacent to the distributed Bragg reflector laser acting as master oscillator exceeds certain values. We investigate the influence of the reflectivity at the facet of the power amplifier on the laser behavior. [ABSTRACT FROM AUTHOR]

We present the strict design parameters of the experiment for the 780 nm tunable continuous-wave second harmonic (SH) generation by the nonlinear resonator containing a MgO doped periodically poled LiNbO (MgO:PPLN) crystal. Optimization of such critical parameters, including focusing and impedance matching, more than 84% SH conversion efficiency and 3.1 W available output power at 780 nm were obtained from the fundamental wave at 1560 nm with two different input couplers. The thermal saturated behavior of the SH output power has been observed in the experiment. The beam quality factor M of the generated SH wave is 1.04 (1.03), and the RMS power stability is 1.29% in 3 h. The SH wave was further used to detect the D transitions of Rb atom, exhibiting a fine tunable characteristic. Such laser source can be a suitable candidate in the atomic physics and quantum optics. [ABSTRACT FROM AUTHOR]

A 50.2W high pulse energy green laser system at 532 nm was demonstrated by extra-cavity second-harmonic generation (SHG). The fundamental laser was based on laser diode (LD) side-pumped MOPA Q-switched technology, producing 79W of average power at the repetition rate of 500 Hz, while the pulse width was 6 ns. Type-II angle phasematched KTiOPO (KTP) crystal was used as the nonlinear crystal. The 50.2W average power of 532 nm laser was obtained with the divergence angle less than 0.6 mrad and the corresponding peak power of 16.7MW. The optical frequency conversion efficiency from fundamental to green laser was up to 63.5%. The measured output power fluctuation was less than 0.38% in one hour operation. [ABSTRACT FROM AUTHOR]

Due to the complex lateral structure of Distributed Feedback lasers (DFB) and Master Oscillator Power Amplifiers (MOPAs), one-dimensional methods like the classical Transfer Matrix Method (TMM) are not suitable for simulating the optical wave in these devices. Therefore, we applied Trigonometric Finite Wave Elements (TFWE) that generalize the TMM in two or three dimensions. By coupling the dynamic wave equation with simplified temperature and drift-diffusion models, we can simulate the dynamic behavior of DFB lasers and MOPAs. Furthermore, by Fourier transformation, we can calculate the modes of the laser cavity and the corresponding wavelengths. By this approach, the influence of injection current and temperature on the resulting modes and output power can be analyzed in detail. [ABSTRACT FROM AUTHOR]

A new laser-wire has been installed in the extraction line of the ATF at KEK. It aims at demonstrating that laser-wires can be used to measure micrometre scale beam size. In parallel, studies have been made to specify a laser suitable for the ILC laser-wires. [ABSTRACT FROM AUTHOR]

This paper reports results of study on self-Q-switched Cr4+, Nd3+: YAG microchip lasers at 1.064 μm using a quasi-monolithic setup. Pulses with 6 to 60 ns wide (FWHM) and TEM00 mode produced under cw pumping with repetition rates ranging from 1.5 kHz to 23 kHz. Pulsed pumping yielded output pulses with repetition rates from 1Hz to several kHz and excellent pulse stability. A pulsed pumped microchip oscillator and flash lamp pumped amplifiers were used to set up a MOPA (Master Oscillator and Power Amplifier) system generating 225 kW pulses with 8 ns width. [ABSTRACT FROM AUTHOR]

A method for increasing the output power of a phase conjugated oscillator (PCO) by using two stimulated-Brillouin-scattering (SBS) cells is described. The average power has been more than doubled and the peak power has been increased by twenty times compared to the single-SBS-cell PCO. Near unity beam quality has been measured. [ABSTRACT FROM AUTHOR]