Analog CMOS design for optical coherence tomography signal detection and processing

Wei Xu, David L. Mathine, Jennifer K. Barton

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


A CMOS circuit was designed and fabricated for optical coherence tomography (OCT) signal detection and processing. The circuit includes a photoreceiver, differential gain stage and lock-in amplifier based demodulator. The photoreceiver consists of a CMOS photodetector and low noise differential transimpedance amplifier which converts the optical interference signal into a voltage. The differential gain stage further amplifies the signal. The in-phase and quadrature channels of the lock-in amplifier each include an analog mixer and switched-capacitor low-pass filter with an external mixer reference signal. The interferogram envelope and phase can be extracted with this configuration, enabling Doppler OCT measurements. A sensitivity of -80 dB is achieved with faithful reproduction of the interferometric signal envelope. A sample image of finger tip is presented.

Original languageEnglish (US)
Pages (from-to)485-489
Number of pages5
JournalIEEE Transactions on Biomedical Engineering
Issue number2
StatePublished - Feb 2008


  • Biomedical imaging
  • CMOS analog integrated circuits
  • Optical tomography

ASJC Scopus subject areas

  • Biomedical Engineering


Dive into the research topics of 'Analog CMOS design for optical coherence tomography signal detection and processing'. Together they form a unique fingerprint.

Cite this