Single-frequency, thin-film-tuned, 06-W, diode-pumped Nd:YVO_4 laser

Abstract

Application of a metallic thin-film selector to the single-frequency oscillation of a diode-pumped Nd:YVO 4 laser has been investigated theoretically and experimentally. We show that a chromium thin-film selector with a thickness between 8 and 9 nm provides single-frequency output within a power range of 0.6 W. Single-frequency operation, slow smooth tuning, or chirping was realized by the output coupler movement with a piezoceramic transducer. Chirping at a repetition rate of 0.5 kHz in the 0.5-10-GHz range was achieved. Physical and technical limitations caused by the wide-gain bandwidth, thermal effects, and mechanical vibrations of cavity elements are discussed.

Solid-state laser with self-stabilized or linearly chirped output frequency

“…In such systems the radiated frequency has to vary linearly versus the time, although in laser with a thin-film selector the frequency changes non-linearly and, sometimes, even by a nonmonotone mode, depending on the position of the selector. The interferometers, which were considered before [2,3] were intended for a single mode selection. Therefore, principal attention was paid to achieve a maximum sharp reflection peak with this interferometer.…”

“…For testing we substitute values of the film parameters close to those that were observed in the experiment [2,3], namely ξ′ = 0.6, ξ′′ = 0.01, R = 0.95, n 1 =1.46, n 2 =1. In Fig.…”

“…It means that in the limits of an intermode space the output frequency would not depend on the position of the thinfilm selector. It is necessary to note, that these conditions are possible with the film faced to an active medium (or a substrate to an output mirror) that is the inverse orientation as compare with the single-frequency operation design [2,3]. In this case, the reflection peak is more wide and smooth and, probably, for sure mode selection it would be necessary to keep the length of an active medium shorter than that used in [2,3].…”

“…For operation in the hospital, in the plant, or in the airport one needs the standard of minor stability but simple, small and relatively cheap. To our mind, the best candidate for this role is the solid-state diode-pumped laser with the thin-film absorbing selector [2,3].…”

<title>Single-frequency diode-pumped laser as a standard for frequency, power, and energy of laser radiation</title>

“…Taking above requirements into account active media based on Nd:YAG and Nd:YVO4 crystals should be preferred, [1,2]. In order to eliminate mechanical disturbances arising when selector is piezoelectrically tuned, what is commonly used for lasers of this type, we propose to put an absorbing layer directly onto the active crystal (without using any piezoelectric converter).…”