Cavity-Enhanced IR Absorption in Planar Chalcogenide Glass Microdisk Resonators: Experiment and Analysis

• Main Authors: Kimerling, Lionel C. (Contributor), Hu, Juejun (Contributor), Carlie, Nathan (Author), Petit, Laeticia (Author), Agarwal, Anuradha Murthy (Contributor)
• Other Authors: MIT Materials Research Laboratory (Contributor), Massachusetts Institute of Technology. Department of Materials Science and Engineering (Contributor)
• Format: Article
• Language: English
• Published: Institute of Electrical and Electronics Engineers, 2010-10-15T19:37:25Z.
• Subjects: Article
• Online Access: Get fulltext

Planar microdisk optical resonators fabricated from Ge[subscript 23]Sb[subscript 7]S[subscript 70] chalcogenide glass on a silicon substrate are applied for cavity-enhanced spectroscopic measurement of chemical molecular absorption fingerprint. A 0.02 cm- 1 detection limit for these devices is demonstrated. This detection limit represents a threefold improvement as compared to a straight waveguide sensor, while the physical device length is reduced by 40-fold. The reduction in device footprint with enhanced sensitivity makes the structure attractive for ldquosensor-on-a-chiprdquo device applications. We also present a design optimization approach for cavity-enhanced IR absorption spectroscopy using traveling-wave resonators, which indicates that further performance improvement can be achieved in optimally coupled, low-loss resonant cavities.
United States. Dept. of Energy (Award DE-SC52-06NA27341)