Measurement-efficient optical wavemeters

Abstract

We describe a method for efficiently determining the wavelength of a monochromatic source and provide an experimental proof-of-concept. The photomeasurement efficiency for a wavemeter can be written as eta(N,q) = (1 + logqN)/m, where N is the number of spectral channels, q is the number of distinguishable output levels per photodetector, and m is the actual number of photomeasurements made. An implementation is developed that achieves a theoretical efficiency of eta(N,q) = 1. The proof-of-concept experiment achieves efficiencies eta = O(1), where the deviation from theory is attributable to well-known optical effects and should be correctable in future versions.

Adaptive millimeter-wave synthetic aperture imaging for compressive sampling of sparse scenes

“…CS has been used to improve sampling efficiency and increase temporal resolution in many imaging systems. In extremely sparse cases, optimal codes can be developed to solve for scatterer information in a number of measurements proportional to the log of the number of locations in the solution space [4]. Unfortunately, determining the optimal code for more than the simplest of systems and with few scatterers becomes impractical.…”

“…The model is then taken as an input to the general framework specified by [18,19]. This method adaptively determines an optimized code based previous measurement, since an a priori optimized code such as in [4] cannot be generated, and RIP cannot be verified for this mode set. The measurement model is then simplified to allow for easier implementation in the adaptive framework, which requires efficient solving of a maximum a posteriori estimate.…”