Newport MKS Multi-Functional Optical Chip Modulator, FOG, 1550 nm M-PY-1550

The M-PY-1550 is the key component of Fiber Optic Gyroscope (FOG) for rotational rate sensing and inertial navigation systems. This Integrated Optic Chip (IOC) device is composed of a polarizer, a Y-junction coupler, and dual electro-optic phase modulators. Based on Lithium Niobate (LiNbO3), M-PY-1550 is fabricated with Proton Exchange (PE) optical waveguides. The M-PY-1550 features Polarization Extinction Ratio (PER) exceeding 60 dB that can minimize bias drift which results from polarization crosstalk-induced nonreciprocity. The M-PY-1550 assures high reliability and performance over a wide temperature range. What is the Pockel's Effect? Both our phase and our amplitude modulators are based upon the Pockel's effect: the electro-optic effect where the refractive index along one or more axes is proportional to an externally applied electric field. Therefore, by applying a voltage across the electrodes of an electro-optic crystal, you can change the phase of light as it passes through the crystal. By placing the crystal between crossed polarizers, this phase modulation can be converted into amplitude modulation. Annealed Proton Exchange (APE) Fabrication Proton Exchange (PE) is one of the common waveguide fabrication techniques in lithium niobate. Compared with Ti in-diffusion, another fabrication method, it can generate higher extraordinary refractive index changes (Δne close to 0.1). A subsequent annealing in a controlled atmosphere, hense called Annealed Proton Exchange (APE), permits a high polarization rejection and a high optical power handling capability, especially for applications using a shorter wavelength than in telecommunications. The annealing, in fact, helps in recovering the nonlinear coefficients that are compromised by standard PE processing.