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.
Highlights
Future microprocessors will need an unprecedented many-core complementary metal oxide semiconductor (CMOS) architecture, and will require dense network management on a chip with a high bit rate and low power consumption that cannot be matched by an electrical interconnect
III–V materials and their photonic devices have been the main players as regards highspeed transceivers in telecom/datacom photonic networks, and are still promising candidates for the construction of these chip-com networks that can be integrated with laser sources, photoreceivers, and other functional nanophotonic devices with ultralow-power consumption well beyond that of group-IV materials
Photoreceivers generally consist of a photodetector (PD) and a trans-impedance amplifier (TIA) to generate sufficient voltage to drive the subsequent electronic circuits, and they are often fully integrated at the CMOS level for short-range optical interconnection [6,7]
Summary
Future microprocessors will need an unprecedented many-core complementary metal oxide semiconductor (CMOS) architecture, and will require dense network management on a chip with a high bit rate and low power consumption that cannot be matched by an electrical interconnect. We have already reported PhC-PDs embedded in an InGaAs absorption layer in an InP-based PhC waveguide, which we obtained using an ultracompact buried-heterostructure (BH) formation [9], and with which we demonstrated a detection bandwidth of around 6 GHz [10] Such a BH technique should provide good applicability for nano-PDs, because this structure can confine both photons and carriers in an ultrasmall space that cannot be achieved by any other PDs. In addition, a lateral p-i-n junction and an air-bridge structure are effective for the reduction of junction capacitance. The potential for integration with InP-based active nano-photonic devices such as all-optical switches, memories, and lasers [12,13,14] with recordlow power consumption is very attractive With these features, the combination of PhC waveguides and InGaAs material offer the possibility of realizing a nano-PD with the smallest size and capacitance yet reported, which has great potential for use as a photoreceiver on a chip. These results reveal a successful way of realizing an ultrasmall/ ultralow-energy photoreceiver that can be densely integrated on a chip
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
