Continuous index IR notch filter for atmospheric CO2 suppression

Arit Shinman; Nuphar N. Lipkin; Roy Kirshner; Hedva Zipin

doi:10.1117/12.453894

23 January 2003 Continuous index IR notch filter for atmospheric CO₂ suppression

Arit Shinman, Nuphar N. Lipkin, Roy Kirshner, Hedva Zipin

Proceedings Volume 4820, Infrared Technology and Applications XXVIII; (2003) https://doi.org/10.1117/12.453894
Event: International Symposium on Optical Science and Technology, 2002, Seattle, WA, United States

Abstract

Rugate optical coatings are films, in which the refractive index is varied in a continuous or quasi-continuous manner. These films are used in order to obtain an optical response that is otherwise difficult to achieve. The application of rugate filters is done by a periodical variation of the refractive index, e.g. sinusoidally. The average index and the index modulation determine the filter bandwidth, and the cycle period determines the notch position. Another unconventional method for filter design, also based on a periodical index variation, is the bragg method, in which notch filters are designed by combining very thin layers of one material in a matrix of another, each unit being λ₀ /2 optical thickness. At the Rafael Optical Coating Center, a CO₂ suppression notch filter was developed using both these methods. A 24 cycles digital rugate film was used to achieve a narrow notch filter with bandwidth of Δλ/λ=6.8%, the transmittance in the blocked area was 13%, and 90% in the rest of the 3-5μm region. With 58 layers bragg film, the achieved blocking was even better - 6% transmittance in the blocking-band center, with a nearly similar transmission in the non- blocked zone.

Citation Download Citation

Arit Shinman, Nuphar N. Lipkin, Roy Kirshner, and Hedva Zipin "Continuous index IR notch filter for atmospheric CO₂ suppression", Proc. SPIE 4820, Infrared Technology and Applications XXVIII, (23 January 2003); https://doi.org/10.1117/12.453894

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available