Measurements of phase retardation and principal axis angle using an electro-optic modulated Mach–Zehnder interferometer

High Frequency Modulation Method for Measuring of Birefringence

“…Combination of precise orientation and controlling bias will set the modulator for correct measurement. If the birefringence sample is then inserted, it may be oriented by maximization the fundamental first harmonic (49.4 kHz) signal [10] and again we have to check operation point via bias voltage.…”

“…If we were able to achieve a modulation depth across the half -wave voltage (V m = V π), using the saw-tooth signal build by function generator, analysis of the AC signal from photodiode would become much simpler [10].…”

An instrument for measuring low optical rotation angle

“…(5), the optical rotation angle can be estimated by two phase-lock extractions and is independent of the retardance of the linearly birefringent material. The phase-locked technique, although has been proposed in previous studies for the measurement of a chiral medium [7,8] or the linearly birefringent medium [11,12], its application to optical rotation measurement in this study is new. Above all, from the inspection of experimental results of glucose solution in front of a half-wave plate, the current system is capable of measuring low rotation angle corresponding to glucose concentration as low as 0.01 g/dl.…”

Polarization mixing error in transmission ellipsometry with two acousto-optical modulators

“…[11][12][13][14][15][16][17][18] To our knowledge, no researches on the polarization mixing error of interferometric transmission ellipsometry have been reported. There are two kinds of errors in heterodyne interferometers, 19 namely, frequency mixing error and polarization mixing error. Frequency mixing error is predominant; polarization mixing error tends to be smaller.…”