Precision synchronous polarimeter with linear response for the measurement of small rotation angles

Abstract

A synchronous polarimeter was set up for the measurement of small rotation angles of the polarization plane of light. The polarimeter is based on a polarizer-Faraday modulator-analyzer structure with a synchronous detection scheme, which produces a linear system response. The theoretical background is studied, and the system performance is investigated experimentally. We achieved an accuracy of the order of 10(-4) deg, or 5 mg/dl of glucose in a 1-cm light path.

Suppression of Noise to Obtain a High-Performance Low-Cost Optical Encoder

“…So, the obtaining of high accuracy, precision, and resolution, directly from the transducer, and without the need to use specialized motion reducers, has always been a motivation for encoder designers. These goals have been partially achieved by [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Every one of them have smart operating principles based on the polarization of light; nevertheless, their commercialization has been frustrated because they are not confident devices from the engineering point of view; thus, research must be made to complete previous designs, for the obtaining of reliable lowcost positioning sensors.…”

Wavefront sensing based on rotated lateral shearing interferometry

“…A third and very interesting method to recover the slope data was pointed out by a referee, uses synchronous processing and is also outlined in [8]. We rewrite Eq.…”

“…Martin Booth is a Royal Academy of Engineering/EPSRC Research Fellow. We would like to thank the anonymous reviewer who did draw our attention to [8] and contributed the idea of processing via synchronous averaging. This work was funded by the Basic Technology scheme of the Research Councils UK and the Lubbock trust.…”

Novel optical polarimeter using an analyzer mounted on rotator 360 stage

“…The proposed polarimeter uses an analyzer mounted on rotator 360 stage instead of employing a Faraday modulator. 8 In order to obtain a linear readout for polarization rotation angle as function of sugar concentration, it is necessary only to apply a coherent phase detector to the polarimeter output signal. 9 In section 2, we review the theory of the saccarimeter and analyze the theoretical performance in the time domain.…”