Grating pair

Lee, B. H. Nishii, J., Dependence of fringe spacing on the grating separation in a long period fiber grating pair, Appl. Opt. 1999, 38, 3450 3459... 

Fig. 6.30 Experimental arrangement for the generation of femtosecond pulses by self-phase-mod-ulation with subsequent pulse compression by a grating pair [686]...

Note The diffraction by the grating causes an additional phase shift which amounts in the first diffraction order to In per grating groove. In reference [687] it is shown, that in spite of this phase shift the delay time of the pulse by the diffraction grating pair is At = S cd) c. 

A typical experimental arrangement is depicted in Fig. 6.30 [686]. The optical pulse from the mode-locked laser is spatially and spectrally broadened in the optical fiber and then compressed by the grating pair. The dispersion of the grating pair can be doubled if the pulse is reflected by the mirror M and passes the grating pair again. Pulse widths of 16 fs have been obtained with such a system [688]. 

Fig. 6.31 Sequence of grating pairs and prism pairs for the compensation of quadratic and cubic phase dispersion. LL and MM are two phase-fronts. The solid line represents a reference path and the dashed line illustrates the paths for the wave of wavelength X, which is diffracted by an angle p at the first grating and refracted by an angle a against the reference path in a prism [689]...

Calculate the separation D of a grating pair that just compensates a spatial dispersion dS/dX = 10 for a center wavelength of 600 nm, a groove spacing of d= m. and angle of incidence a = 30°. 

Fig. 4.4 Schematic diagram of an aperture-type scanning near-field optical microscope. TSL Ti Sapphire laser, GP Grating pair, ODL Optical delay line, CH Mechanical chopper wheel, CWL CW laser, XL Xe lamp, WP Wave plates, FC Fiber coupler, OF Optical fiber, S Sample substrate, NFP Near-field probe, PST Piezo driven stage, OB Objective lens, POL Polarizer, FIL Optical filter, MC Monochromator, CCD Charge coupled device, PD Photodiode...

Fig. 11.36. (a) Schematic diagram of chirped pulse amplification (CPA) (b) P sign of pulse stretcher with a grating pair [11.95]... 

We will now discuss the different components of this process in more detail. The oscillator consists of one of the femtosecond devices discussed previously. The pulse stretcher uses a grating pair, where the two gratings, however, are not parallel as for pulse compression, but are tilted against each other (Fig. 11.36b). This increases the path difference between the blue and the red components in the pulse and stretches the pulse length. An aberration-free pulse stretcher with two curved mirrors and a grating is described in [11.96] and is depicted in Fig. 11.37. 

Kay BD, Peden CHF, Goodman DW (1986) Kinetics of hydrogen absorption by Pd(llO). Phys Rev B 34 817-822 Kim YH, Kim MJ, Park M, Jang J, Lee BH (2008) Hydrogen sensor based on a palladium-coated long-period fiber grating pair. J Opt Soc Korea 12(4) 221-225... 

Fig.9.21. Pulse compression using spectral broadening in an optical fibre and subsequent wavelength-dependent retardation in a grating pair...

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