Abstract:
Acoustical ringing which results from piezoelectric effects in an electro-optical modulator is suppressed by mounting the modulator crystal between massive, acoustically absorbent, support members which also provide an electric circuit interface for applying electric signals to the modulator. Solder provides such an absorbent mounting for a lithium tantalate electrooptical modulator crystal. Both solder support members are applied during the same heating interval and permitted to cool simultaneously. In one embodiment the solder application is accomplished in a first step wherein mounds of solder are applied adjacent to the crystal at a first temperature and in a second step wherein additional solder is applied at a lower temperature between the crystal and the solder mounds.
Abstract:
A lithium tantalate crystal is configured to have plural surfaces for producing sufficient internal reflection of a light beam to effect approximately a complete phase reversal of one component of the electric vector, which vector is transverse to the direction of propagation, of the beam within the crystal between two separate electrooptic modulation operations on the same beam within that crystal.
Abstract:
A METHOD FOR PRODUCING HIGH CONTRAST PHOTOGRAPHIC IMAGES. FROM THE LOW CONTRAST ORIGINAL, A FIRST COPY IS MADE ON HIGH CONTRAST FILM, THEREBY REVERSING THE IMAGE. EXPOSURE TIME IS CONTROLLED IN ORDER TO UNDEREXPOSE THE LIGHTEST AREAS WHICH SHOULD HAVE BEEN OPAQUE IN THE ORIGINAL. FROM THIS COPY, A SECOND COPY IS MADE ON HIGH CONTRAST FILM, AGAIN REVERSING THE IMAGE. AGAIN, THE LIGHTEST AREAS OF THE FIRST COPY WHICH SHOULD HAVE BEEN OPAQUE ARE UNDEREXPOSED BY CONTROLLING THE EXPOSURE TIME. THESE AREAS CORRESPOND TO THE DAREST AREAS IN THE ORIGINAL TRANSPARENCY WHICH SHOULD HAVE BEEN LIGHT. BY CORRECTLY CONTROLLING THE EXPOSURE TIMES OF THESE TWO STEPS, A TRANSPARENCY IS PRODUCED WITH NEARLY BINARY DENSITY SCALE, THUS PRODUCING A HIGH CONTRAST MASK SUITABLE FOR PHOTOETCHING.