Photonics Research, 2019, 7 (8): 08000828, Published Online: Jul. 11, 2019
Ge-on-Si modulators operating at mid-infrared wavelengths up to 8 μm
Abstract
We report mid-infrared Ge-on-Si waveguide-based PIN diode modulators operating at wavelengths of 3.8 and 8 μm. Fabricated 1-mm-long electro-absorption devices exhibit a modulation depth of > 35 dB with a 7 V forward bias at 3.8 μm, and a similar 1-mm-long Mach–Zehnder modulator has a V π · L of 0.47 V · cm . Driven by a 2.5V p p RF signal, 60 MHz on-off keying modulation was demonstrated. Electro-absorption modulation at 8 μm was demonstrated preliminarily, with the device performance limited by large contact separation and high contact resistance.
Tiantian Li, Milos Nedeljkovic, Nannicha Hattasan, Wei Cao, Zhibo Qu, Callum G. Littlejohns, Jordi Soler Penades, Lorenzo Mastronardi, Vinita Mittal, Daniel Benedikovic, David J. Thomson, Frederic Y. Gardes, Hequan Wu, Zhiping Zhou, Goran Z. Mashanovich. Ge-on-Si modulators operating at mid-infrared wavelengths up to 8 μm[J]. Photonics Research, 2019, 7(8): 08000828.