Photonic-crystal nano-photodetector with ultrasmall capacitance for on-chip light-to-voltage conversion without an amplifier

Nozaki, K., Matsuo, S., Fujii, T., Takeda, K., Ono, M., Shakoor, A. , Kuramochi, E. and Notomi, M. (2016) Photonic-crystal nano-photodetector with ultrasmall capacitance for on-chip light-to-voltage conversion without an amplifier. Optica, 3(5), p. 483. (doi: 10.1364/OPTICA.3.000483)

Abstract

The power consumption of a conventional photoreceiver is dominated by that of the electric amplifier connected to the photodetector (PD). An ultralow-capacitance PD can overcome this limitation, because it can generate sufficiently large voltage without an amplifier when combined with a high-impedance load. In this work, we demonstrate an ultracompact InGaAs PD based on a photonic crystal waveguide with a length of only 1.7 μm and a capacitance of less than 1 fF. Despite the small size of the device, a high responsivity of 1 A/W and a clear 40 Gbit/s eye diagram are observed, overcoming the conventional trade-off between size and responsivity. A resistor-loaded PD was actually fabricated for light-to-voltage conversion, and a kilo-volt/watt efficiency with a gigahertz bandwidth even without amplifiers was measured with an electro-optic probe. Combined experimental and theoretical results reveal that a bandwidth in excess of 10 GHz can be expected, leading to an ultralow energy consumption of less than 1 fJ/bit for the photoreceiver. Amplifier-less PDs with attractive performance levels are therefore feasible and a step toward a densely integrated photonic network/processor on a chip.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Shakoor, Dr Abdul
• Authors: Nozaki, K., Matsuo, S., Fujii, T., Takeda, K., Ono, M., Shakoor, A., Kuramochi, E., and Notomi, M.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: Optica
• Publisher: The Optical Society
• ISSN: 2334-2536
• Published Online: 05 May 2016
• Copyright Holders: Copyright © 2016 Optical Society of America
• First Published: First published in Optica 3(5):483-492
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher