Most Popular Articles
Working In The Basement: Measuring Signals Below The Noise Floor With A Lock-In Amplifier
By Shimon Elstein, senior physicist, Ophir Photonics

The measurement of optical signals in the femtowatt to nanowatt range can be extremely difficult as signal levels this low are typically lost in detector noise levels and swamped by background light. Photodiode detectors that operate within small bandwidths have a noise floor of only 1 picowatt. This article presents the advantages of using lock-in amplifiers for measuring signals below the noise floor, and how they work.

Minimizing Trade-Offs Between Spectral Smoothing And Resolution
By Ocean Optics

Boxcar smoothing is a convenient way to smooth out noise in a spectrum, enabling peaks of interest to be more easily viewed, defined, and characterized for properties like peak intensity, center wavelength, and FWHM (full width half maximum). It is a convenient complement to spectral averaging, particularly to minimize acquisition times, but must be used judiciously to avoid impacting the spectral resolution of the data acquired.

Investigating The Thermal Physiology Of Birds And Mammals
Many details of the thermal biology of animals are unknown. To fill the gaps in this knowledge, researchers at the Institute of Biodiversity, Animal Health and Comparative Medicine at the University of Glasgow, Scotland, are using thermal imaging to learn as much as possible in order to help animals in the long run.
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