1. An Optical Input Module With Superconducting Single-Flux-Quantum Circuit Operating at 1550 nm.
- Author
-
Terai, H., Shinada, S., Makise, K., Wang, Z., and Wada, N.
- Subjects
- *
PHOTONICS , *OPTICAL detectors , *CASCADE converters , *DIGITAL electronics , *PHOTODIODES , *ELECTRIC lines , *MICROFABRICATION - Abstract
We developed an optical input module consisting of built-in metal-semiconductor-metal photodiodes (MSM-PDs) and co-planar waveguide transmission lines fabricated on an InP substrate, which is flip-chip bonded with a single-flux-quantum (SFQ) circuit fabricated on a Si substrate. To improve photosensitivity of the MSM-PD for a wavelength above 1530 nm at 4 K, we tested the MSM-PDs made of lattice mismatched In1-xGa_xAs films on InP substrates. By employing In1-xGa_xAs with x=0.44, an apparent reduction of photosensitivity for a wavelength above 1530 nm was suppressed. We also tested newly designed DC/SFQ converters with higher input current sensitivities. The observed current sensitivity was improved to 41 \muA, while that in the conventional DC/SFQ converter was 140 \muA. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF