GB1014230A - Improvements in or relating to optical filters - Google Patents

Improvements in or relating to optical filters

Info

Publication number
GB1014230A
GB1014230A GB2959553A GB2959553A GB1014230A GB 1014230 A GB1014230 A GB 1014230A GB 2959553 A GB2959553 A GB 2959553A GB 2959553 A GB2959553 A GB 2959553A GB 1014230 A GB1014230 A GB 1014230A
Authority
GB
United Kingdom
Prior art keywords
germanium
base
coating
deposition
carbon
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB2959553A
Inventor
John Charnock
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mullard Radio Valve Co Ltd
Original Assignee
Mullard Radio Valve Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mullard Radio Valve Co Ltd filed Critical Mullard Radio Valve Co Ltd
Priority to GB2959553A priority Critical patent/GB1014230A/en
Publication of GB1014230A publication Critical patent/GB1014230A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/20—Filters
    • G02B5/28—Interference filters
    • G02B5/285—Interference filters comprising deposited thin solid films
    • G02B5/286—Interference filters comprising deposited thin solid films having four or fewer layers, e.g. for achieving a colour effect

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Physical Vapour Deposition (AREA)
  • Surface Treatment Of Glass (AREA)

Abstract

An infra-red optical filter comprising a coating of germanium on a transparent base is produced by heating the base to 200 DEG C. or more while the germanium is being deposited by evaporation-deposition. In this way a thick coating (e.g. 0.001 inch) is produced with less tendency to flake. Preferably the deposition is in two or more stages and the germanium is evaporated from an electrically conductive boat of tantalum, molybdenum or carbon. Carbon is preferred as the germanium alloys with the metals if the boat is used a few times. The base may be of glass plate, rock salt, synthetic sapphire or periclase or of "Kodial" or "Pyrex" (Registered Trade Marks) glass. The latter are particularly suitable with a thermal expansion coefficient similar to germanium. If the germanium is evaporated upwards the base may be heated with an electrically heated copper slug. After formation of the coating, blooming may be effected with zinc sulphide or metallic selenium.
GB2959553A 1953-10-26 1953-10-26 Improvements in or relating to optical filters Expired GB1014230A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB2959553A GB1014230A (en) 1953-10-26 1953-10-26 Improvements in or relating to optical filters

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2959553A GB1014230A (en) 1953-10-26 1953-10-26 Improvements in or relating to optical filters

Publications (1)

Publication Number Publication Date
GB1014230A true GB1014230A (en) 1965-12-22

Family

ID=10294019

Family Applications (1)

Application Number Title Priority Date Filing Date
GB2959553A Expired GB1014230A (en) 1953-10-26 1953-10-26 Improvements in or relating to optical filters

Country Status (1)

Country Link
GB (1) GB1014230A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4459484A (en) * 1980-12-03 1984-07-10 Cerberus Ag Radiation detector for a flame alarm
GB2218606A (en) * 1987-08-06 1989-11-22 Stc Plc Wavelength selective filter

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4459484A (en) * 1980-12-03 1984-07-10 Cerberus Ag Radiation detector for a flame alarm
GB2218606A (en) * 1987-08-06 1989-11-22 Stc Plc Wavelength selective filter
GB2218606B (en) * 1987-08-06 1991-01-30 Stc Plc Wavelength selective filter

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