Diode pumped lasers

Thulium is one of the most expensive of the rare earths, and therefore has little applications (Emsley 2001). Thulium is used as a dopant in YAG and YLF. Efficient flash lamp and laser diode-pumped laser operation has been achieved in Tm " YAG and Tm " YLF co-doped either with Cr " or Ho ". Thulium is also used in thulium-doped holmium lasers, which have outputs in the 2 pm region, a wavelength range of interest for coherent radar systems, remote sensing and medical applications (Koechner 2006). 

Fig. 9.7 Schematic diagram of the laser cavity and VPS laser diode pumping system. Reproduced with permission from [90]. Copyright 2002, Elsevier...

Fig. 9.7 shows schematic diagram of the laser cavity and VPS laser diode pumping system [90]. Nd YAG ceramic rods, with a dimension of 04 mm x 105 mm and 0.6 at.% Nd, were used for the experiments, with flat end faces that were antireflection-coated at 1064 nm. Two concave mirrors, both with curvature of 500 mm, were used to form the laser cavity. One was high-reflectivity-coated, and the other had a reflectivity of about 80 % at the laser wavelength. Figure 9.8 show the laser outputs at 1064 nm as a function of pump power [90]. At the pump power of... 

Almost transform-limited 357-fs pulses at the center wavelength of 1033.5 nm, with a maximum average power of 352 mW, were achieved in this case. The efficiency against the absorbed pump power was 32 %, by using a laser diode pumping at a repetition rate of 97 MHz. 

Dong J, Ueda K, Yagi H, Kaminskii AA (2008) Laser-diode pumped seU-Q-switched... 

Otsuka K, Ohtomo T (2008) Polarization properties of laser-diode-pumped micro-grained Nd YAG eeramie lasers. Laser Phys Lett 5 659-663... 

Tokunaga K, Chu SC, Hsiao HY, Ohtomo T, Otsuka K (2009) Spontaneous Mathieu-Gauss mode oscillation in micro-grained Nd YAG ceramic lasers with azimuth laser-diode pumping. Laser Phys Lett 6 635-638... 

In 1987, another important step was the laser diode pumping Reekie et al. (1987) expected to pave the way for inline amplification at 1.5 pm, which was later demonstrated to be true. That same year they obtained the first fiber amplifier at 1.5 pm (Mears et al. 1987) (fig. 40), giving a gain of 28 dB for a length of 3 m, with an amplification bandwidth of more than 4THz (30 nm). 

A novel device for efficiently generating intense radiation at wavelengths around 202 nm is shown in Fig. 5.110. A laser diode-pumped Nd YV04 laser is frequency doubled and delivers intense radiation at X = 532 nm, which is again frequency doubled to A. = 266 nm in a BBO crystal inside a ring resonator. The output from this resonator is superimposed in a third enhancement cavity with the output from a diode laser at A = 850 nm to generate radiation at A = 202 nm by sum-frequency mixing. This 202-nm radiation is polarized perpendicularly to that at the two other waves and can be therefore efficiently coupled out of the cavity by a Brewster plate [5.255]. 

K. Ueda, N. Uehara Laser diode pumped solid state lasers for gravitational wave antenna. Proc. SPIE 1837, 337 (1992)... 

V. Karpov, E.M. Dianov, V.M. Paramonov, O.I. Medvedkov Laser-diode pumped phospho-silicate-fiber Raman laser with an output of 1 W at 1.48 pm. Opt. Lett. 24, 1 (1999)... 

M.J. McCarthy and D.C. Hanna, Continuous-Wave Mode-Locked Singly Resonant Optical Parametric Oscillator Synchronously Pumped by a Laser-Diode-Pumped Nd-.YLF Laser , Opt. Lett. 17, 402 (1992). 

B. Zhou, T.J. Kane, G.J. Dixon, R.L. Byen Efficient, frequency-stable laser-diode-pumped NdYAG laser. Opt. Lett. 10, 62 (1985)... 

R.L. Byer, G.J. Dixon, T.J. Kane, W. Kozlovsky, B. Zhou Frequency-doubled, laser diode pumped, miniature Nd YAG oscillator - progress toward an all solid state sub-kilohertz linewidth coherent source, in Laser Spectroscopy VII, ed. by... 

Introduction to Laser Diode-Pumped Solid State Lasers, Richard Scheps, Vol. TT53... 

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