Alejandro D. Farinas

Injection locking of a 13-W cw Nd:YAG ring laser

A lamp-pumped, 13-W cw Nd:YAG ring laser at 1.064 microm is injection locked using a 40-mW single-frequency diodelaser-pumped Nd:YAG laser as the master oscillator. The phase fidelity of the injected slave to the master is measured using an all-optical technique.

Design and characterization of a 5.5-W, cw, injection-locked, fiber-coupled, laser-diode-pumped Nd:YAG miniature-slab laser

We have built a laser-diode-pumped Nd:YAG laser that emits 5.5 W of power in a single-frequency, polarized, nearly diffraction-limited TEM00 mode. The laser uses fiber-coupled pump lasers and a rectilinear geometry to achieve high efficiency in a simple side-pumped architecture. Injection locking produces a stable, single-frequency output with no intracavity frequency-selection elements.

Demonstration of a low bandwidth 1.06 mu m optical phase-locked loop for coherent homodyne communication

A type-II, 1.06- mu m, optical phase-locked-loop (OPLL) for use in a coherent homodyne receiver is discussed. Diode-laser-pumped solid-state lasers are used for both the local oscillator and transmitter, because their phase noise is significantly lower than that of diode lasers. Closed-loop RMS phase noise of less than 12 mrad (0.69 degrees ) is achieved, and modulation-demodulation in bulk modulators at rates from 20 kHz to 20 MHz with less than 19 degrees of modulation depth is demonstrated.<<ETX>>

Narrow-Linewidth Operation of Diode-Laser-Pumped Nonplanar Ring Oscillators

The search for gravity waves, improved tests of relativity theory, advances in high resolution spectroscopy, and optical frequency standard development impose stringent requirements on the linewidth and frequency stability of lasers. Most efforts to produce narrow linewidth lasers have focused on He-Ne, dye, argon ion, or semiconductor lasers. These lasers exhibit free-running linewidths ranging from tens of kilohertz to several gigahertz and thus require wideband servo techniques for narrow linewidth operation [1]. Diode-laser-pumped monolithic solid-state lasers, on the other hand, can have free-running linewidths of a few kilohertz [2, 3], which makes them attractive candidates for narrow linewidth operation using low bandwith servo techniques. The short-term free-running stability is attributed to the small size and rigidity of the monolithic laser, which makes the optical cavity resistant to acoustical excitation, and to the low noise and efficiency of the diode laser pumping. Of particular interest are the diode-laser-pumped monolithic NonPlanar Ring Oscillators (NPROs) that overcome the problems of spatial hole burning and sensitivity to optical feedback inherent in linear cavity lasers [3, 4, 5]. Here we present our current NPRO design and explain its properties, discuss our recent narrow linewidth results obtained by locking a pair of diode-laser-pumped Nd:GGG NPROs to an optical cavity, and speculate about future developments.

Self-aligning pinhole system

A practical self-aligning pinhole (SAP) system, capable of actively aligning a pinhole to an incident optical beam, has been demonstrated. The enabling technology for the SAP is a silicon micromachined pinhole (SiMP). The SiMP is an example of a simple optical element fabricated from silicon in order to take advantage of both the mechanical structure allowed by micromachining technology and the electrical structures allowed by semiconductor technology. To complete the transformation from an enabling technology to a working system, development was necessary in packaging, mechanical mounting and operation, and algorithms.

Amplitude and frequency stability of a 5 W injection-locked, laser-diode pumped, Nd:YAG miniature-slab laser

Gravitational-wave detectors1 require a laser that provides single-frequency, polarized, fundamental-mode output at high power. Ideally, the laser would also be reliable and efficient, capable of being operated 24 hours per day for years. In addition, the laser must meet stringent amplitude, frequency and beam-pointing stability requirements. While specially-modified, commercially-available, argon-ion lasers have been used in gravitational-wave interferometry, they do not meet the reliability, output power and electrical efficiency requirements of the next generation of gravitational-wave receivers.2 In this paper, we describe the performance of a laser-diode-pumped, Nd:YAG laser, designed to meet the source requirements of an advanced gravitational-wave detector.