Abstract
We introduce a novel digital lock-in detection technique for simultaneously measuring the amplitude and phase of multiple amplitude-modulated signals. Using particular modulation and sampling constraints and averaging filters, we achieve optimal noise reduction and discrimination between sources of different modulation frequencies. Furthermore, it is shown that the digital lock-in technique can be performed as a simple matrix multiplication, which considerably reduces the computation time. The digital lock-in algorithm is described and analyzed under certain sampling and modulation conditions, and results are shown for both numerical and experimental data.
Original language | English (US) |
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Pages (from-to) | 182-189 |
Number of pages | 8 |
Journal | IEEE Transactions on Instrumentation and Measurement |
Volume | 57 |
Issue number | 1 |
DOIs | |
State | Published - 2008 |
Keywords
- Digital lock-in detection
- Lock-in amplifier
- Optical tomography
- Phase-sensitive detection
- Spectroscopy
- Synchronous detection
ASJC Scopus subject areas
- Instrumentation
- Electrical and Electronic Engineering