Travelling wave electrode structures and methods for optical modulators

Abstract

Compared to directly modulated lasers, external modulation of continuous wave (CW) lasers can provide a greater modulation bandwidth, thereby further increasing data transmission rates. These external modulators can be phase modulators, amplitude modulators, or combinations thereof. In most material systems, the speed mismatch between optical and electrical signals must be compensated to achieve the desired bandwidth, while simultaneously increasing the device length to reduce the drive voltage. In some material systems, such as silicon used in silicon photonics, this requires slowing down the optical signal. Therefore, achieving this goal without increasing the optical losses of the modulator is advantageous.

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