Grating grooves

SRGs recorded with circularly polarized beams showed an even more interesting erasure behavior. The SRG can be erased by beams polarized parallel to the grooves and circularly polarized, as in the previous cases, but when erasing was tried with a beam polarized perpendicularly to the grating grooves an increase in diffraction efficiency and amplification of the surface modulation occurred (44% increase in the amplitude of the SRG, consistent with doubling of the diffraction efficiency). 

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. 

Figure 14. Principle of the grating Beams retlecled at the grating grooves overlap, giving constructive interference at an angle P for each wavelength except the zero-order case. The separation (resolution) of wavelength maxima 5 on a projection surface for the second order is twice that for the first order.

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