Apparatus and method for optical heterodyne conversion
US5663639A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 18, 1994 |
| Grant date | Sep 2, 1997 |
| Priority date | — |
| Expiry date | Jan 18, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E10/50
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An apparatus and method for optical heterodyne conversion and a radiation source and integrated diagnostics using the apparatus and method are disclosed. The radiation source can operate in a high-power narrow-band mode in which a constant-frequency output is provided or in a low-power broadband mode in which the frequency is tunable to allow the radiation source to act as a sweep oscillator. The apparatus or photomixer includes two sets of interdigitated conductive electrodes formed on top of a crystal lattice formed of column III-V compounds, particularly InAlGaAs compounds. Additional column V atoms are interspersed within the lattice structure to form defect energy states in the bandgap of the host material. The region of the material between the interdigitated electrodes is illuminated by optical radiation containing two different frequencies. Photon absorption in the material causes a current at the difference frequency to be generated and coupled to the interdigitated electrodes. The current is then coupled to a planar transmission line or antenna structure to generate coherent, continuous-wave, unimodal radiation in the microwave, millimeter-wave, or submillimeter-wave regi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.