Jul 22 – 26, 2019
Europe/Rome timezone

Microwave SQUID multiplexer for readout of optical TES array

Jul 23, 2019, 5:45 PM
1h 15m
Piazza Città di Lombardia (Milano)

Piazza Città di Lombardia


Piazza Città di Lombardia, 1, 20124 Milano MI
Poster Detector readout, signal processing, and related technologies Poster session


Mr Naoki Nakada (AIST)


Optical Transition Edge Sensor (TES) detectors are highly desirable for two-dimensional single-photon multi-color imaging, especially in biology. Recently, we have demonstrated the single photon spectroscopic imaging with an optical TES [1]. It takes 20 to 40 minutes to obtain an image. To decrease the measurement time, multi-pixel detectors are necessary. A Microwave SQUID Multiplexer (MW-Mux) [2] which consists of superconducting resonators and rf-SQUID is a powerful device for readout of the optical TES array.
In previous work, we successfully measured output signals of an optical TES with MW-Mux. Fig. 1 shows the energy spectrum of faint light source with a wavelength of 1550 nm. The observed energy resolution of 0.42 eV for the single photon peak (= 0.8 eV) was worse than that measured with dc-SQUID (0.27 eV).
In this research, we considered the degradation of the energy resolution which is caused by the high-frequency cutoff. There are two main factors that limit the frequency band. The first one is a loss of waveform information due to a low sampling frequency compared with the inverse of time constant of the optical TES. The second one is a bandwidth of the resonator. We simulated the effect of the first one on the energy resolution. The sum of the intrinsic energy resolution (0.27 eV), readout noise (0.07 eV) and the simulated result (0.25 eV) was 0.37 eV. This is consistent with the experimental energy resolution. We will discuss the requirement of frequency band of MW-Mux to improve the energy resolution.
Energy spectrum measured by an optical TES with MW-Mux

[1] Niwa et al. Scientific Reports 7 (2017) 45660.
[2] J. A. B. Mates et al., Appl. Phys. Lett. 92, 023514 (2008).

This work was supported by JST-CREST Grant Number JPMJCR17N4, Japan. MW-Mux chips were fabricated in CRAVITY (Cleanroom for analogue digital superconductivity) in AIST.

Less than 5 years of experience since completion of Ph.D N
Student (Ph.D., M.Sc. or B.Sc.) Y

Primary author

Mr Naoki Nakada (AIST)


Dr Kaori Hattori (AIST) Mr Yuki Nakashima (ISAS/JAXA) Dr Fuminori Hirayama (AIST) Dr Ryo Yamamoto (AIST) Dr Hitrotake Yamamori (AIST) Dr Satoshi Kohjiro (AIST) Dr Akira Sato (AIST) Prof. Hiroyuki Takahashi (School of Engineering, The University of Tokyo) Dr Daiji Fukuda (National Institute of Advanced Industrial Science and Technology)

Presentation materials