Lasers frequency doubling

Dye lasers, frequency doubled if necessary, provide ideal sources for such experiments. The radiation is very intense, the line width is small ( 1 cm ) and the wavenumber may be tuned to match any absorption band in the visible or near-ultraviolet region. 

Figure 8.8 Very large crystals such as this sample of KDP (KH2PO4) used for laser frequency doubling are produced by careful nucleation control at the metastable boundary between an unsaturated and supersaturated solution (image courtesy of the Lawrence Livermore National Laboratory).

The photoisomerization is induced by irradiation with green light (532 nm) from either a continuous laser or pulsed laser (frequency doubled Nd.-YAG Q-switched laser operated in single pulse mode). The second harmonic is generated by a pulsed optical source such as produced by NdrYLF (1053 nm) or Nd YAG (1064 nm) Q-switched nanosecond laser. The probe... 

YAG (frequency doubled) YAG (frequency quadrupled) Diode lasers Frequency doubled (LiNbOs)... 

For this reason many investigations have been carried out at low temperatures. In order to examine the excited states of the nucleic acids with lasers, frequency doubled dye lasers or NdrYAG lasers have to be used, because the nucleic acids absorb below 310 nm (Fig. 1, 2). An experimental arrangement for the observation of fluorescence in solution after excitation with a pulsed dye laser in the visible and UV down to 220 nm is shown in Fig. 7 18,44). 

Fig. 9.91 Exciting the hydrogen 15-25 transition with two counterpropagating photons in a standing-wave field at 243 nm. This radiation is obtained from a dye laser frequency doubled in a BBO crystal and stabilized to a reference cavity. While scanning the hydrogen resonance the frequency of this laser is measured with a frequency comb to be 2 466 061413 187 074 (34) Hz for the hy-perfine centroid [1327]...

Jurdik et al. (2002)). It should be noted that, for a number of fixed-wavelength lasers (such as NdrYAG lasers), frequency doubling is implemented in intra-cavity configurations, which exhibit the benefit of automatic resonator-enhanced circulating power of the pump wave conversion efficiencies of more than 50 per cent are routinely achieved in commercial green CW Nd YAG laser systems, and values of close to 90 per cent are not uncommon (e.g. see Schneider et al. (1996)). 

The first dye laser, developed independently by Schafer [5.168] and Sorokin [5.169] in 1966, was pumped by a ruby laser. In the early days of dye laser development, giant-pulse ruby lasers, frequency-doubled Ndiglass lasers, and nitrogen lasers were the main pumping sources. All these lasers have sufficiently short pulse durations Tp, which are shorter than the intersystem crossing time constant 7ic(Si -> Ti). 

Laser Ho Tm LuLiF laser Frequency-doubled Nd YAG laser ... 

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