Temperature and current dependence of Doppler SNR in a VCSEL based self-mixing sensor

Ranveer S. Matharu, Yah Leng Lim, Russell Kliese, Karl Bertling, A. Ashrif A. Bakar, Julien Perchoux, A. D. Rakic

Research output: Chapter in Book/Report/Conference proceedingConference proceedingpeer-review


This paper proposes a method for maintaining the maximum signal-to-noise ratio (SNR) of the signal obtained from the self-mixing sensor based on a Vertical-Cavity Surface-Emitting Laser (VCSEL). The SNR of the Doppler self-mixing signal was investigated experimentally as a function of laser driving current and ambient temperature. It was found that the locus of the maximum SNR in the current-temperature space can be well approximated by the simple analytical model based on the temperature behaviour of the VCSELs threshold current. A selfmixing Doppler signal was acquired from the variation in VCSEL junction voltage rather than from a conventional variation in laser optical power to reduce the complexity of the system. It was found that the optimum sensor performance over a wide range of ambient temperatures can be achieved by tuning the laser current according to the proposed model. This enables the sensor to operate without temperature stabilisation making it attractive for mobile applications and applications with limited power supply.

Original languageEnglish
Title of host publicationIEEE Sensors 2009 Conference - SENSORS 2009
Number of pages4
Publication statusPublished - 1 Dec 2009
Externally publishedYes
EventIEEE Sensors 2009 Conference - Christchurch, New Zealand
Duration: 25 Oct 200928 Oct 2009

Publication series

NameProceedings of IEEE Sensors


ConferenceIEEE Sensors 2009 Conference
Abbreviated titleSENSORS 2009
Country/TerritoryNew Zealand

ASJC Scopus subject areas

  • Electrical and Electronic Engineering


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