Improved Large Signal Analysis of the Dual-Wavelength Linearization Technique of Optically Phase-Modulated Analog Microwave Signals

This paper presents simple closed-form expressions, in terms of the ordinary Bessel functions, for the amplitudes of the third- and fifth-order intermodulation products of the dual-wavelength linearized phase modulated link for any scenario of the microwave driving voltage. The results obtained for a microwave driving voltage comprising equal-amplitude two- and three-tones show that the third-order intermodulation can be minimized for values of phase modulation depth less than 0.2 over a relatively wide range of the ratio between the powers in the TM and TE waves of the link. Using these results it is possible to adjust the phase modulation depth and/or the ratio between the powers of the TM and TE waves to achieve a dual-wavelength linearized phase modulated link with a predetermined intermodulation performance.