Optical filter and method of manufacturing the same
US6933001B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 14, 2002 |
| Grant date | Aug 23, 2005 |
| Priority date | — |
| Expiry date | Mar 20, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B5/285
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The optical thickness of a film formed on a substrate is controlled precisely to manufacture an optical filter having an accurate optical thickness. Time is counted during a film being formed on a substrate to note time points t with respect to a reference time set in advance. At least one of two optical characteristics of energy transmittance and energy reflectance when the film being formed on the substrate is irradiated with monitoring light is expressed by a function f(t) of the time points t based on a theoretical formula of the optical characteristic. The optical characteristic is measured by irradiating the film with the monitoring light at the time points t. A designed thickness achieving time at which the optical thickness of the film designed thickness is predicted. The film formation is stopped at the designed thickness achieving time, thereby obtaining the optical filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.