Tunable subnanosecond laser pulse generation using an active mirror concept

Abstract

We report (theory, experimental check) an improved approach for generation of a tunable, subnanosecond pulse (0.1-0.4 ns), based on a single pulsation ("spike") separation from the transient oscillations in a dye laser with active mirror (AMIR). A pumping by 20-50 ns pulses from Q-switched Nd:YAG laser is considered. The separation is in original, two-spectral selective channels cavity, where the forced by AMIR quenched generation at one of the wavelength stops initially started spiking generation at the other wavelength after the first spike development. The AMIR quickly starts the quenching generation at a precisely controlled moment and with necessary intensity thus assuring the desired separation. An advantage is a high reproducibility of the separation for high (∼250%) pump power fluctuations combined with tuning in large range (∼20 nm). To obtain such an operation we form ∼1 ns leading front pump pulse by electrooptical temporal cutting of the input pump pulse and use an optical delay line. This increases also a few times the power in the separated spike (to be ∼100 kW). Our approach widens the combinations of lasers for effective applications of spike separation technique (dye lasers excited by Q-switched solid-state or Cu-vapor lasers).

Development of Original Optical and Quantum Electronics Devices for Applications in Communications, Metrology and Sciences

“…The development include ideas, experiments, theory and proposed applications developed by us. It is applicable in the case of limited diameter beam illumination [Nenchev, 1982;Nenchev, 1993;Stoykova, 1993;Deneva, 2007;Deneva, 1996]. The new proposition, except our previosly introduced new optical element based on a Reflecting Interference Wedge [Nenchev, 1982], includes a new WDM (wavelength division multiplexing) element with an important property allowing spectral tuning of inputs/outputs in the simplest manner.…”

“…Inspired by IW incorporation in laser design, over the recent years we focused our efforts on the study of compact wedged interference structures under illumination with a narrow light beam of small diameter. We have succeeded to reveal unique properties of the IW when illuminated with laser light, and to propose various applications, thus insuring the IW as a competitive optical element in laser resonator design [Deneva, 2007;Louyer, 2003;Goris-Neveux, 1995]. A high-reflectivity coating IW with thickness of tens of millimetres has spectral resolution comparable to that of the Fabry-Perot interferometer, but at additional advantage of linear spectral tuning by means of translation in its plane.…”

“…A simple and effective solution of a multiwavelength spectrally selective resonant structure for two-wavelength lasers with independent tuning at each wavelength has been proposed by the authors [Nenchev, 1981;Deneva, 2007;Louyer, 2003, Gorris-Neveux, 1995. It makes the use of valuable optical features of the IWs.…”

“…In detail, the original approach for realizing subnanosecond tunable laser is presented in our paper [Deneva, 2007]. The essence of the principle is to restrict the starting pulse-like generation with subnanosecond pulsations (~0.1 -0.2 ns, "spikes") to single pulsation by using an active mirror, which forces damping the competitive generation in the second selective channel.…”