Littrow grating

Littrow mounting spect The arrangement of the grating and other components of a Littrow grating spectrograph, which is analogous to that of a Littrow quartz spectrograph. li tro, maunt-ir ... 

Fig. 4.20. (a) Littrow mount of a grating with p = a. (b) Illustration of blaze angle for a Littrow grating... 

In laser-spectroscopic applications the case a = often occurs, which means that the light is reflected back into the direction of the incident light. For such an arrangement, called a Littrow-grating mount (shown in Fig. 4.20), the grating equation (4.21) for constructive interference reduces to... 

Maximum reflectivity of the Littrow grating is achieved for / = r = 0 = or (Fig. 4.20b). The Littrow grating acts as a wavelength-selective reflector because light is only reflected if the incident wavelength satisfies the condition (4.21a). 

Calculate the number of grooves/mm for a Littrow grating for a 25° incidence at X = 488nm (i.e., the first diffraction order is being reflected back into the incident beam at an angle a = 25° to the grating normal). 

Because most prism materials such as glass or quartz absorb in the infrared region, it is more convenient to use a Littrow grating (Sect. 4.1) as wavelength selector in this wavelength range. Figure 5.28 illustrates the line selection in... 

Fig. 5.28. Selection of CO2 laser lines corresponding to different rotational transitions by a Littrow grating...

Another realization of tunable single-mode diode lasers uses a Littrow grating, which couples part of the laser output back into the gain medium (Fig. 5.68) [5.121]. When the grating with a groove spacing dg is tilted by an... 

Fig. 5.68a,b. Continuously tunable diode laser with Littrow grating (a) experimental setup, and (b) geometric condition for the location of the tilting axis for the grating. The rotation around point R compensates only in first order, around R2 in second order [5.122]... 

Fig.5.83, Hansch-type dye laser with transverse pumping and beam expander [5.171]. The wavelength is tuned by turning the Littrow grating. Light with a different wavelength Xd + AX is diffracted out of the resonator...

Fig. 5.86. Littman laser with grazing incidence grating and Littrow grating using longitudinal pumping...

M. de Labachelerie, G. Passedat Mode-hop suppression of Littrow grating-tuned lasers. Appl. Opt. 32, 269 (1993)... 

Figure 5.45 Short Hansch-type dye laser cavity with Littrow grating and mode selection either with an internal etalon or an external FPI as mode filter [348]...

Figure 5.77 External-cavity diode laser with transmission Littrow grating...

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