Thermal optical switches for light
US5828799A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 20, 1997 |
| Grant date | Oct 27, 1998 |
| Priority date | — |
| Expiry date | Oct 20, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/3576
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A thermal optical switching cell has a channel of either gas or boilable liquid that crosses an optical waveguide at a forty-five degree angle. Two or more appropriately placed heaters use the water/steam/dry states of thermal ink jet technology to quickly insert, or extract, boilable liquid respectively into, or from, the channel. The boilable liquid has an index of refraction close to that of the guide. In the wet state, the channel contains the liquid and nearly all the light of the incoming guide traverses the liquid along the axis of the guide. In the dry state, the channel contains gas. Total internal reflection (TIR) occurs and light is directed at right angles away from the axis of the incoming channel. Adding a second waveguide, perpendicular to, and intersecting the first waveguide at the channel, forms a cross-bar switch. These liquid switching cells toggle between the wet and dry states. No power is required to hold the switch in the most recent state. A monitoring signal is described that can be used to determine the state of the switch. The dry state of these cells is totally internally reflecting. The wet state, however, is transmissive with a small, but objectionabl…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.