Photodichroic Silicate Glass Surface

Che-Kuang Wu

doi:10.1117/12.7972602

1 October 1980 Photodichroic Silicate Glass Surface

Che-Kuang Wu

Author Affiliations +

Optical Engineering, Vol. 19, Issue 5, 195769 (October 1980). https://doi.org/10.1117/12.7972602

Abstract

The photodichroic silicate glass surface is a direct-read-after-write laser recording material which permits instant optical recording without processing of any kind. The required writing energy density at mega Hz rate and higher is 40 mj/cm2. An even better writing sensitivity is expected for a preconditioned glass surface which is yet to be demonstrated at mega Hz rates. The inherent resolution capability of this material is better than 2000 cycles/mm, which is consistent with the fine grain structure of the photodichroic silicate glass surface (grain size <0.02 pm). The photodichroic silicate glass surface can be pre-recorded with tracks of width 1 µm or less. It is potentially a pinhole-free recording material due to the inherent homogeneity of the silicate glasses, and to the very small sizes of the photosensitive crystals, relative to the wavelength of light and the thickness of the photosensitive glass sur-face layer. The physical effect of recording is irreversible; yet the recorded spots or bits are erasable. The erased 1-bit can be distinguished easily from the 0-bit (of course, not distinguishable in the normal read mode), when necessary. There is also a mechanism to prevent erasing after recording and error corrections are completed. The writing is done with a polarized red light, and nondestructive read is done using a near infrared beam, with the recorded bits between crossed polarizers. The erasure is to re-expose with the write beam whose polarization direction has been rotated 45° with respect to the initial polarization exposure direction. In this manuscript, the physical effect of recording is discussed in detail, including the intensity dependent writing sensitivity, the threshold effect, and the relationships among observed spot size, contrast and the writing energy density. Recording in mega Hz rates as well as write-erase cycling are demonstrated.

Citation Download Citation

Che-Kuang Wu "Photodichroic Silicate Glass Surface," Optical Engineering 19(5), 195769 (1 October 1980). https://doi.org/10.1117/12.7972602

Published: 1 October 1980

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available