Reflection interference filter

• US 2,590,906 A
• Filed: 11/22/1946
• Issued: 04/01/1952
• Est. Priority Date: 11/22/1946
• Status: Expired due to Term

• Current Assignee: Kenneth F. Tripp
• Original Assignee: Kenneth F. Tripp
• Inventors: Tripp, Kenneth F.
• Application Number:
  US02/711,561
• Time in Patent Office: 1,957 Days
• US Class Current: 359/584
• CPC Class Codes: G02B 5/284 of etalon type comprising a resonant cavity other than a thin solid film, e.g. gas, air, solid plates etalons for fibre optic multiplexing G02B6/29358; etalons for spectral measurement G01J3/26

Claims

1. AN OPTICAL REFLECTION FILTER OPERATING BY LIGHT RAY INTERFERENCE AND ABSORPTION COMPRISING A SUBSTANTIALLY OPAQUE LAYER OF A METAL SELECTED FROM THE GROUP CONSISTING OF SILVER AND ALUMINUM, SAID OPAQUE LAYER BEING DEPOSITED ON A GLASS SUPPORT, A SUBSTANTIALLY TRANSPARENT LAYER OF A DIELECTRIC SELECTED FROM THE GROUP CONSISTING OF MAGNESIUM FLUORIDE AND CALCIUM FLUORIDE, SAID TRANSPARENT LAYER BEING DEPOSITED ON SAID OPAQUE LAYER AND HAVING A THICKNESS NOT EXCEEDING 10<

/N IN WHICH<

REPRESENTS A WAVE LENGTH AT WHICH THE FILTER REFLECTS A MAXIMUM OF LIGHT AND N REPRESENTS THE INDEX OF REFRACTION OF SAID TRANSPARENT LAYER, AND A SEMITRANSPARENT LAYER OF A METAL SELECTED FROM THE GROUP CONSISTING OF SILVER AND ALUMINUM, SAID SEMITRANSPARENT LAYER BEING DEPOSITED ON SAID TRANSPARENT LAYER AND HAVING A TRANSMISSION BETWEEN SUBSTANTIALLY 25% AND 65%.