Measurement of birefringence in integrated optical waveguides by use of a microwave-modulated optical wave

We present a technique for measuring birefringence (B) in integrated optical waveguides by use of a microwave-modulated optical wave. It is shown that the technique is able to yield an accurate measurement of birefringence. In addition, an approximate estimate of birefringence dispersion (dB/dλ) can be achieved by means of tuning the wavelength of the light source and measuring the dependence of the birefringence on the wavelength. As an example of the use of the technique, we show how to evaluate an innovative Ti:LiNbO3 waveguide. The results show that such a Ti:LiNbO3 waveguide has a birefringence of 0.0783±0.0001 and a birefringence dispersion of 0.05±0.01 μm-1 when the optical wavelength is approximately 1.560 μm.