Nipi refractive index modulation apparatus and method
US4784476A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 27, 1987 |
| Grant date | Nov 15, 1988 |
| Priority date | — |
| Expiry date | Jan 27, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F1/0151
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Various optical modulation systems and methods are disclosed which are based upon modulating the refractive index of a nipi structure. The refractive index modulation is accomplished by applying a controlled voltage differential across the n-doped and p-doped layers of the structure. Staggered contacts to the layers are formed by conductive elements which extend through the structure. One of the elements establishes ohmic contacts with the n layers, and the other with the p-layers. When implemented as an optical spatial phase modulator, one of the nipi contacts is provided as a grid which divides the structure into a matrix of pixel elements, with the other contact comprising separate wires extending through each pixel. A spatial voltage pattern is applied to the pixel wires to inject charge into their corresponding layers, and thereby modulate the refractive indices of the pixels. This imposes a desired spatial phase modulation onto a readout beam transmitted through the nipi structure. Various guided wave applications are also disclosed in which a beam is transmitted through a nipi structure parallel to the n and p layers. The nipi sturcture is not divided into pixels, but rather…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.