Abstract
We present two variations of a novel interferometry technique capable of simultaneously measuring multiple targets with high sensitivity. The technique performs a homodyne phase measurement by application of a four point phase shifting algorithm, with pseudo-random switching between points to allow multiplexed measurement based upon propagation delay alone. By multiplexing measurements and shifting complexity into signal processing, both variants realise significant complexity reductions over comparable methods. The first variant performs a typical coherent detection with a dedicated reference field and achieves a displacement noise floor 0.8pm/vHz above 50Hz. The second allows for removal of the dedicated reference, resulting in further simplifications and improved low frequency performance with a 1pm/vHz noise floor measured down to 20Hz. These results represent the most sensitive measurement performed using this style of interferometry whilst simultaneously reducing the electro-optic footprint.
Original language | English |
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Pages (from-to) | 22195-22207 |
Number of pages | 13 |
Journal | Optics Express |
Volume | 20 |
Issue number | 20 |
DOIs | |
Publication status | Published - 24 Sept 2012 |