GB1387483A - Process for the production of integrated optical elements - Google Patents

Abstract

1387483 Photographic process BAYER A G 1 March 1972 [2 March 1971] 9532/72 Heading G2X Integrated optical elements (e.g. wave-guides) are produced by exposing at least part of the surface of a radiation-sensitive material to at least one electromagnetic surface wave (as defined), and if necessary or desired photographically processing, thereby producing a change in refractive index in the exposed areas. A waveguide may be formed Fig.2 (not shown) by exposing a photo-sensitive layer (2) on a support (7) and immersed in a liquid having a very high refractive index (CH 2 I 2 ) to homogeneous coherent radiation directed for total internal reflection at the surface of layer (2) so that surface waves are formed in the layer producing a periodically varying refractive index in the surface. Grid couplers followed by waveguides are produced by forming an interference pattern with these surface waves, either by using a beam of homogeneous coherent radiation directed perpendicular to the surface Fig.3 (not shown) or another set of surface waves from the same or opposite direction Fig.4 (not shown). In the Examples the exposure is effected using a laser and the photo-sensitive layer is either (1) a AgBr/l emulsion which after exposure is prehardened, rinsed, developed, fixed, rinsed, bleached rinsed, treated in successive alcohol baths and dried; the bleaching is effected using a mixture of (A) aqueous CuSO 4 , KBr and citric acid and (B) aqueous H 2 O 2 or with (A) alone followed by (A) + (B); (2) a photo-sensitive vinyl polymer; or (3) bichromated gelatine which after exposure is simultaneously steep-hardened and desensitized.