Optimization of displacement-measuring quadrature interferometers considering the real properties of optical components

Abstract

We present the influence of alignment and the real properties of optical components on the performance of a two-detector homodyne displacement-measuring quadrature laser interferometer. An experimental method, based on the optimization of visibility and sensitivity, was established and theoretically described to assess the performance and stability of the interferometer. We show that the optimal performance of such interferometers is achieved with the iterative alignment procedure described.

High-resolution detection of small distance changes by an optical frequency comb

“…optical resonator (X-axis). The scale of the homodyne Michelson interferometer was not compensated by the method [6]. The bottom record shows the difference between these both measuring systems.…”

“…Research teams in the world works on various measuring methods based on a laser interferometry [6]. But the most precise systems use an optical resonator as a measuring device.…”

Dual-probe homodyne quadrature laser interferometer

“…Ideally, the interferometer has to be aligned so that the signals x and y are in quadrature. This means that 90 deg phase difference, between the signals, needs to be achieved with proper optical alignment and choice of optical components [17]. If in addition to the quadrature of optical phases between the photodiode signals (p 0 0), ac amplitudes are made equal (A x A y ), then the sensitivity is constant, i.e., independent of the optical phase δ 4πu∕λ and consequently independent on displacement difference u.…”

Interferometric dynamic displacement measurement using phase-modulated light along with stepwise control of operation point

“…One solution for this is an interferometer with in-phase and quadrature-phase out-puts, whereby we can obtain a signal in proportion to the displacement. [5][6][7][8] Such interferometers have many advantages, but their optical and electrical circuit arrangements should be carefully adjusted, 9) which is generally complex. In contrast, the single-output homodyne interferometer has a simple structure, although its nonlinear output usually requires control of the OPD.…”