Mosaic-pixelated Fabry-Pérot filters for snapshot spectral imagers

C. C. Cheung; M. Christophersen

doi:10.1117/12.2674062

20 October 2023 Mosaic-pixelated Fabry-Pérot filters for snapshot spectral imagers

C. C. Cheung, M. Christophersen

Proceedings Volume 12688, Imaging Spectrometry XXVI: Applications, Sensors, and Processing; 1268808 (2023) https://doi.org/10.1117/12.2674062
Event: SPIE Optical Engineering + Applications, 2023, San Diego, California, United States

Abstract

Multispectral and hyperspectral sensors are used today in a wide range of applications. One approach to multispectral imaging uses mosaicked Fabry-Pérot filters on a per-pixel basis over an entire sensor array. They offer single-shot or snapshot spectral imaging over two-dimensional scenes without scanning over wavelengths or along a spatial axis. These multispectral imagers are an extension of the conventional Bayer 2 × 2 (red-green-green-blue) pattern, which means they offer customized spectral responses with an option for an increased number of channels compared to the classic Bayer-color imager. We designed and microfabricated prototype mosaic Fabry-Pérot filters for snapshot imagers where the spectral filters are directly bonded onto an image sensor. Our Fabry-Pérot filters are made of silicon oxide layers with different etalon heights, fabricated onto fused silica wafers, and sandwiched between two dielectric mirrors. The different heights of the oxides are fabricated by using grayscale lithography and reactive ion etching. Grayscale lithography allows for producing mosaic patterns with various heights using a single lithography step. We present results from our custom-designed prototype full-frame (centimeter-scale) 2×2 mosaicked etalon filter arrays. The topographies (height distribution and roughness) of the different mosaic elements were characterized using optical profilometry. The measured transmission curves from several designs offer a range of broad- and narrow-band optical (~400-800 nm) spectral responses. Improvements in uniformities of surface shapes, roughness, and sharper edges were achieved using “Advanced Diffuser-Based Gray-tone Lithography" as discussed in a companion contribution at this meeting.

Conference Presentation

(2023) Published by SPIE. Downloading of the abstract is permitted for personal use only.

Citation Download Citation

C. C. Cheung and M. Christophersen "Mosaic-pixelated Fabry-Pérot filters for snapshot spectral imagers", Proc. SPIE 12688, Imaging Spectrometry XXVI: Applications, Sensors, and Processing, 1268808 (20 October 2023); https://doi.org/10.1117/12.2674062

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