Signal distortion noise in volume phase holograms

Signal distortion noise in volume phase holograms is analysed for the case in which the object beam consists of two plane waves. It is shown that, for a given (on-Bragg) signal diffraction efficiency, the magnitude of the signal distortion noise is inversely proportional to the square of crystal thickness. Furthermore, as a function of the angular position of the reconstruction beam, the signal distortion noise has two peaks: one at the Bragg angle and the other at a deviation Δθ 0 from the Bragg angle, where Δθ 0 is a function of relative angles between the components of the object beam and the reference beam. The on-Bragg peak of the signal distortion noise is experimentally located for volume phase holograms recorded in Fe-doped LiNbO 3. The measured angular position is found to be in accord with the calculated value. © 1977 Chapman and Hall

FUNDAMENTAL TUNNELING PROCESSES IN MOSa SOLAR CELLS

In previous studies of tunneling through a MOSa tunnel junction, where Sa was a-Si : H, it was shown that their characteristics resemble those of MOSc devices where Sc was crystalline silicon. In the present work we would like to report a demonstration of fundamental tunneling processes in such tunnel junctions. In particular, the transition from semiconductor controlled regime to tunneling controlled regime can be clearly distinguished. The present results represent one of the rare cases where a fundamental semiconductor process is demonstrated more clearly in an amorphous semiconductor device than in a crystalline semiconductor device. Following the above findings we have identified tunneling into forbidden-gap states and we got a qualitative map of the state distribution in the forbidden-gap

Amorphous thin films for solar-cell applications : final report for period September 11, 1979 - September 10, 1980 /

"Work Performed Under Contract No. AC02-77CH00178.""October 1980.""Prepared under Subcontract no. XJ-9-8254."Includes bibliographical references (page 83-85).Mode of access: Internet