If a voltage is applied across one of the arms, a phase shift is induced for the wave passing through that arm. A simple and fast frequency domain analysis method for. Hence a highly accurate model for microwave and optical propagation in an electrooptic modulator is needed that includes the loss in the modulating electrodes and in the inhomogeneous semicon. Mtf is used for components as simple as a spherical singlet lens to those as complex as a multielement telecentric imaging lens assembly.
In order to model the fmmr modulator, we use the jacobianger function expansion method. Amplitude and phase transfer functions of an optical modulator francis p. When optical designers attempt to compare the performance of optical systems, a commonly used measure is the modulation transfer function mtf. These power losses obtained by comparing mzi output power before and after au electrodes depositions. The group index ng is used to determine the freespectral rangefsr, which can be visualized as the shift in effective index vs. Mzi modulator with the two voltages on the same arm pag. Therefore, the nonlinearity at the output of a siliconbased mzi modulator is originated basically from. Without taking into account any polarization effects, a possible approach to describe the transfer function of the device is to use the transfer matrix theory 10. The output is a result of interference, ranging from. Therefore, the nonlinearity at the output of a siliconbased mzi modulator is originated basically from the operating bias point of the modulator nonlinear transfer function combined with the intrinsic nonlinear response of. A machzehnder modulator is used for controlling the amplitude of an optical wave. Design, fabrication and analysis of a machzehnder interferometer user. Transfer function of mzi modulator in asymmetric configuration pag. Hvam abstract in this letter, we propose a technique based on heterodyne detection for accurately and simultaneously measuring the amplitude and phase transfer functions of.
Introduction to modulation transfer function when optical designers attempt to compare the performance of optical systems, a commonly used measure is the modulation transfer function mtf. The allfiber mzi structure for optical dpsk demodulation. The input waveguide is split up into two waveguide interferometer arms. Introduction to modulation transfer function edmund optics. Without applied electric field, constructive interference was achieved at the. Two phase modulators can be placed in parallel using an interferometric structure. Mach zehnder interferometer mzi modulator, resonatorassisted mach zehnder. Bias controller of machzehnder modulator for electrooptic. Interference of two waves when two monochromatic waves of complex amplitudes u1r and. Heterodyne technique for measuring the amplitude and phase.
Waveguide linbo3 intensity modulators are mach zehnder type interferometers. Similarly, the output of a machzehnder interferometer is given by. The linear nature of the lorentzian transfer function for the rrm is utilized over the sinusoidal transfer function within mzi modulators offering significant improvement in mpl sfdr. Machzehnder modulator, intensity modulation, and mzm drift 1. Since the pulse is related to ng, information always travels slower than the phase velocity vp which is related to neff. The machzehnder modulator mzm has been widely used for broadband photonic analog. The incoming light is split into two branches, different phase shifts applies to each path, and then recombined. The fraction of phase shift required term is calculated as a function of mzi er assuming it is biased at its quadrature point. Design of gan based optical modulator with machzehnder. The derivation of the second term is simplified by noting that the mzi maximum output 1. External modulators and mathematical modeling of mach zehnder. It is well known that a cosine transfer function can present high or low. The relation between in and out ports of the passive device is written as 5. In this theory, 22 matrices are used to represent transformation of fields.