November 2018
Spotlight Summary by Robert Magnusson
Optical spectrometer based on continuously-chirped guided mode resonance filter
By cleverly applying the guided-mode resonance (GMR) effect, Hung and colleagues demonstrate a compact spectrometer with excellent attributes. Using first a chirped resonant grating on a waveguide film with a fixed thickness, there results a spectrum with varying resonance linewidth and efficiency relative to period, or position, along the spectrometer. In contrast, combining the chirped grating with a waveguide film that is mildly graded in thickness along the grating vector yields a constant linewidth and efficiency. Natural for GMR filters, the resonance linewidth depends on the polarization state of the input light. Thus, this chip-type spectrometer exhibits sub-nm resolution in TM polarization and around 4 nm in TE polarization while working across the 500- to 700-nm spectral range. The authors verify successful operation of their instrument by measuring spectra of a white LED as well as laser sources and then comparing these with spectra obtained with a commercial spectrum analyzer. This work exemplifies the potential of the GMR effect to enable platform technologies on which many beneficial applications could be based.
You must log in to add comments.
Add Comment
You must log in to add comments.
Article Information
Optical spectrometer based on continuously-chirped guided mode resonance filter
Yung-Jr Hung, Chia-Wei Kao, Tzu-Chieh Kao, Chia-Wei Huang, Jia-Jin Lin, and Chuan-Ci Yin
Opt. Express 26(21) 27515-27527 (2018) View: HTML | PDF