title: Optical transmission modules for multi-channel superconducting quantum interference device readouts.
abstract: We developed an optical transmission module consisting of 16-channel analog-to-digital converter (ADC), digital-noise filter, and one-line serial transmitter, which transferred Superconducting Quantum Interference Device (SQUID) readout data to a computer by a single optical cable. A 16-channel ADC sent out SQUID readouts data with 32-bit serial data of 8-bit channel and 24-bit voltage data at a sample rate of 1.5 kSample/s. A digital-noise filter suppressed digital noises generated by digital clocks to obtain SQUID modulation as large as possible. One-line serial transmitter reformed 32-bit serial data to the modulated data that contained data and clock, and sent them through a single optical cable. When the optical transmission modules were applied to 152-channel SQUID magnetoencephalography system, this system maintained a field noise level of 3 fT/√Hz @ 100 Hz.
authors.affiliation: Brain Cognition Measurement Center, Korea Research Institute of Standards and Science, Daejeon 305-600, South Korea.
authors.forename: Jin-Mok
authors.initials: JM
authors.lastname: Kim
authors.affiliation: Brain Cognition Measurement Center, Korea Research Institute of Standards and Science, Daejeon 305-600, South Korea.
authors.forename: Hyukchan
authors.initials: H
authors.lastname: Kwon
authors.affiliation: Brain Cognition Measurement Center, Korea Research Institute of Standards and Science, Daejeon 305-600, South Korea.
authors.forename: Kwon-kyu
authors.initials: KK
authors.lastname: Yu
authors.affiliation: Brain Cognition Measurement Center, Korea Research Institute of Standards and Science, Daejeon 305-600, South Korea.
authors.forename: Yong-Ho
authors.initials: YH
authors.lastname: Lee
authors.affiliation: Brain Cognition Measurement Center, Korea Research Institute of Standards and Science, Daejeon 305-600, South Korea.
authors.forename: Kiwoong
authors.initials: K
authors.lastname: Kim
mesh_terms: D000703:Analog-Digital Conversion; D004553:Electric Conductivity; D055615:Electrical Equipment and Supplies; D004574:Electromagnetic Fields; D015225:Magnetoencephalography / Q000295:instrumentation / Q000379:methods*; D055620:Optical Phenomena