[OPTICAL REVIEW Vol. 8, No. 5 (2001) 315-317]

Azodye Gelatin Films for Polarization Holographic Recording

Mario IVANOV1,2,* and Tomoaki EIJU2

1Central Laboratory of Optical Storage and Processing of Information, Bulgarian Academy of Sciences, Sofia, Bulgaria, 2National Institute of Advanced Industrial Science and Technology, 1-1-1, Namiki, Tsukuba, 305-8561 Japan

(Received April 2, 2001; Accepted July 21, 2001)

Mordant pure yellow azodye in a matrix of gelatin is proposed as a medium for stable polarization recording. Relatively high values of birefringence are measured (over Δ n= 0.02). Polarization diffraction gratings are recorded with two circularly polarized waves and diffraction efficiency of 67% is achieved at 633 nm. Protected from the humidity, the recording is stable. Long-term radiation by a 633 nm probe beam is harmless as well. Unusual behaviour is observed when acting on the recorded grating alternatively with one of the recording beams. The left circularly polarized beam erases the grating sharply, while the right circularly polarized beam, before erasure, initially increases the diffraction efficiency.

Key words : azodye, azo-dye, polarization holography, polarization diffraction grating, circular analyzer

m.ivanov@aist.go.jp