Abstract

Lithium Niobate (LN) is a basic material of integrated optics, for example for electro and acousto-optical modulators, switches, diffraction gratings, nonlinear optical wavelength converters and others [1]. LN based ion exchange or Ti-indiffused contact photolithographic techniques are established technologies, however, finite tolerance of optical elements could not respond some modern applications. For example, high-purity suppressed carrier synthesis or high extinction ratio pulse generation for precision measurement systems require additional active trimming electrodes [2] at the device and corresponding servo loop. Recently developed direct laser writing (DLW) of femtosecond/ultrafast laser pulses [3] can be employed to address the problem, but this method is problematic for mass production and suffer from high insertion loss in optical waveguides (typically ~ 1 dB/cm compared to <0.1 dB/cm for Ti in-diffused waveguides).

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