Generation of subnanosecond CO2 laser pulses at 10.6 μm by pulse compression techniques

Abstract

The results of an investigation of the time evolution of a mode-locked pulse produced by a CO2 laser passively mode locked with an In-doped Ge bleachable absorber are presented. The observed pulse shortening is explained by a simple theory of pulse compression due to the saturable absorber. Pulse durations as short as 400 ps are observed.

Thomson Backscattering from an Intense Relativistic Electron Beam as a Diagnostic for a Free Electron Laser

“…(*) The pulse width of the mode-locked laser output is about 3 ns (see figure III.6 or Feldman and Figueira , 1974). The linewidth is obtained by taking the inverse of the pulse width, which is consistent with the inhomogeneous Doppler broadening at this temperature and pressure.…”

Experimental study of passive laser pulse compression in a fluorescent dye medium

“…The pulse at the right side is the incident pulse. As mentioned before, the compression is a consequence of saturation in absorption, and has been studied in detail by many authors (9)(10)(11)(12)(13)(14)(15). As such, we did not study this aspect and have concentrated only on the influence of (TE on the transmission.…”

Low-Temperature PECVD Growth of Germanium for Mode-Locking of Er-Doped Fiber Laser

“…In addition to the well-known slow and fast SAs for fiber lasers, recently, germanium (Ge) was also considered as another promising candidate to serve as a fast SA due to its ultrafast recovery time (sub-picosecond degree) and nonlinear saturable absorption [ 42 , 43 , 44 ]. In previous works, the passive mode-locking laser with the Ge SA was preliminarily explored as early as the 1970s [ 45 , 46 , 47 , 48 ]. The saturation intensity and the modulation depth of Ge-based SA were reported as 10 MW/cm 2 at 10.6 μm and 0.13% at 1.54 μm, respectively [ 42 , 45 , 49 ].…”

“…The saturation intensity and the modulation depth of Ge-based SA were reported as 10 MW/cm 2 at 10.6 μm and 0.13% at 1.54 μm, respectively [ 42 , 45 , 49 ]. Although the CO 2 laser was mode-locked by Ge SA at 10.6 μm in previous works [ 47 ], the operational wavelength was far beyond the wavelength required for fiber-optic communications or ultrafast optoelectronic applications in nearby C- and L-band wavelength regimes. Furthermore, the manufacturing process of the saturable Bragg reflector (SBR) structure based on a 40 nm thick Ge film deposited by chemical vapor deposition (CVD) is relatively complex [ 42 ].…”