Injection locking and mode selection in TEA-CO<inf>2</inf>laser oscillators

Abstract

The injection of a master oscillator signal in a high-power evolution of the different field amplitudes and phases together with TEACOz laser is analyzed and a dynamic model is formulated to repre-their effect on the inversion. A study over a wide range of injection sent the interaction.Based on the competition between the injected levels and detuning frequencies clearly indicates three distinct regions signal and the spontaneous emission, the model describes the transient of operation: a spontaneous oscillationzone, amode-selection zone, and a frequency-locking zone. The main predictions of the model are Manuscript

A narrow-band injection-seeded pulsed titanium:sapphire oscillator-amplifier system with on-line chirp analysis for high-resolution spectroscopy

“…Such an effect, referred to as the "cavity mode pulling," has been observed before in other laser materials. 23,24 Also in a theoretical model by Bowers and Moody, 25 it is predicted that the output of injection-seeded pulsed laser systems, where the cavity round trip time is much shorter than the actual buildup time, the longitudinal mode structure of the cavity rather than the seed frequency, determines the center frequency of the output pulses. The seed frequency merely selects the cavity resonance frequency at which the output is pulled to.…”

“…They preprogrammed pulse envelopes, in the range of durations between 10 ns and 1 s, by acoustooptical modulator ͑AOM͒ intensity modulating the output of a cw Ti:sapphire laser and subsequently amplifying these in a series of multipass amplifiers; this led to XUV pulses at bandwidths as low as 55 MHz. 10 Dupré and Miller extended the development of injection-seeded pulsed Ti:sapphire lasers, focusing on methods to optimize cavity stabilization, to achieve pulse energies of 100 mJ at bandwidths as low as [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] MHz ͓full width at half maximum ͑FWHM͔͒ for use in high-resolution spectroscopy. 11 When using injection-seeded pulsed laser systems in high-resolution spectroscopic applications, either at the fundamental wavelength or at generated harmonics, effects of time-dependent gain in the amplifier will give rise to phase excursions deviating from the carrier wave.…”

Instabilities in lasers with an injected signal

“…13, where pulsing in the intensity and in the phase is predicted when the external field is not strong enough to lock the system. However, the region of interest remains the locked one, and different treatments have been made of homogeneouslyl 3 -' 5 and inhomogeneously broadened lasers' 5 to establish the general requirements in terms of the detuning and the amplitude of the external signal in order to reach injection locking. A preliminary study of the unstable region is given in Refs.…”

The transient evolution of AM mode locking a TEA CO2laser

“…The various collisional rates [9] in the above equations are where x, y, and z are, respectively, the COz, N2, and He partial pressures in atmospheres. According to Gilbert's model, the pumping rates can be approximated as…”