Development of THz Astronomy in China
Sheng-Cai Shi & SMLab Team
Purple Mountain Observatory
Chinese Academy of Sciences

1

I. Terahertz Matters in Astronomy
THz(FIR/submm/mm)

ALMAFASTHerschel
Image credits: NASA/ESA/ALMA/FAST2

A Window Seeing Cold/Dark Universe

Dole et al., 2006, A&A, 451, 417

CMB
anisotropies& PGW
Image credits: NASA/ESA/JCMT

Ivison et al. 2000

SCUBA (contour) vs HST (image)!Dark” submm sources w/o optical IDs

Stellar light

Stellar light
Last scattering
absorbed &surface
reemitted by dust

Negative K-correction effect3

A Window with Rich Fingerprints
Pre-biotic signatures/building blocks of life

THz/FIR lines for redshift,
SFR & metallicity

MACS1149-JD1@ z=9.11/13.26Gly

Image credits: ALMA/Origins/Chris Walker

EcologyofISM
4

A Window with Highest Spatial Resolution
EHT @ 230GHz

Image credits: EHT/NASA5

II. THz Astronomy Developed in China
from space to Qinghai to Antarctic6Mm-Wave Astronomy in China
1995
3-mm-band
Schottky receiver
1982
Constructing the 1st mmwave telescope in China

2002
multi-line SIS
receiver1998
1st SIS receiver in China

2010
3x3 multibeamSIS receiver
Schottky

SIS
7Superconducting SIS Mixers for ALMA
no SIS, no ALMASISSIS

PCTJ
Band4
125~163GHz

Band8385~500GHz

Band10787~950GHz

8

From Space to Qinghai to Antarctic
HSTDM⁃ 0.5-THz receiver w/ NbN SIS @ 10K⁃ onboard CSST w/ China’s space station⁃ to be launched 2023/2024

THz/FIR facilities at Dome A
15-m Submm Telescope⁃ Site: Qinghai⁃ Freq. band: 0.1~0.5/0.66 THz⁃ Instruments: SIS rx, KID camera, …
9

Atmospheric Transmission at Zenith at Three Sites
Winter

SiteWinterPWV (median)Dome A

Apr ~ Sep

158mm

XSMC

Oct ~Mar950mm

10New THz/FIR Windows at Dome A
S.C. Shi et al, Nature Astronomy 1 (2016)

Dome-A
THz/FIR facilities⁃ 4093m⁃ -83℃ in winter⁃ 60km x 10km
11

III. Superconducting Mixers & Detectors at PMO
10 µm

SIS

HEB

TES

KID

12

High-Energy-Gap NbN SIS for Space Applications!" #$ !"!

9.5K

⎯ NbN SIS in collaboration
with NiCT (Japan)⎯ High sensitivity @ ～10K

~16K

⎯ 1st astronomicalapplication
J. Li et al, APL 92 (2008)

CITHz instrument onboard CSSTTHz
Wave13Superconducting HEB Mixers: from THz to MIR!)*+))',-,898")6:%;7µ--&%12+

1 µm!"#$%&'("')*+))'",-, #.$+&/0)1./*%)2"345"6%7+&<6'2+=":>;,-L:%

Electron-temperature
distribution on HEB

LMicrobridgeµ--&%12+

Contacts

Contacts

Physics:

Substrate!w

dpheatingelectrons
T e, Cet e -eElectronst e - phPe® pphonons
Tp, Cpt ph -ePp®ePhononst esPp®s

substrate Tb

Non-equilibrium electro-thermaltransport/feedback & fluctuation
3+'*"-'(')/+"+?# @0&"+(+/*&0)#"A"$B0)0)#"
P (T ( x), w ) I 02 r (Te ( x))¶¶[le (Te ( x)) T e( x)] - s ep (Te ( x) 3.6 - Tp3.6 ) + LO e+=0
¶x
¶x2LA
¶¶
4
[l p (Tp ) T p] - s pp (Tp4 - Tsubstrate) + s ep (Te3.6 - Tp3.6 ) = 0
¶x
¶x

14

THz/MIR HEB Mixers Developed at PMO
1.00.8!"#$%"&'()

0.6
0.4

30

2000

MeasuredFitted curve
Regular Residual
Simulation

0.2Trec20
151000

hot 10cold500

IF Power (µ W)

251500Trec (K)Normalized response (a.u.)-- in collaboration with MSPU/SRON/LERMA

50-20.0-10120Voltage (mV)

75010001250

1500

Frequency (GHz)W. Miao et al, APL 104 (2014); APL 118 (2021)

K.M. Zhou et al, IEEE/AS 25 (2015)

Trx=450K @ 1.4THz

W. Miao et al. OE 23 (2015)

Y. Ren et al, AIP Advances (2019)

5hn/kB @ ~28THz

15

First Lab Detection of 3.5-THz CH3OH with HEB/QCL
CH3OH甲醇Emission

1.00.50.00300600900
IF Frequency (MHz)Phase-locking & stabilized HEB/QCL System(SRON/PMO collaboration)

Brightness Temperature (K)300

Y. Ren et al, APL 97 (2010); APL 98 (2011) APL 100/101 (2012)

1500

0.93mBar

1503001.33mBar

1503001.72mBar

1503002.15mBar

1503002.64mBar

150800

1200

1000

1200

IF frequency (MHz )

1400

16

Science Drivers with THz Camera
Only 7 objects with spectroscopic
redshift determination for z>7.5

Large-scale structure（e.g. EoR）
LIM w/ CII,OIII, high-J CO et al

CMB anisotropies & PGW

THz “SDSS”

Imaging w/ TES & KID

Imaging w/ TES & KID

Credits: J Borrill, COBE/WMAP/Planck, SDSS, NAOJ

17

TES – from Mm-wave/CMB to X-Ray/IFU
Transition Edge Sensor
PhotonEnergy E

Thermometer
Absorber, C

Weak thermal link, G

Physics:
Weak electron-phonon coupling & fluctuation
DT = E / C
t＝C / Gt eff = t /(1 + a I / n)T ¶R
R0 ¶Ta I＝ 0
Heat sink @TbathI ¶R
b I＝ 0R0 ¶I

R ( I , T ) = R ( I 0 , T0 ) +¶R ( I , T )¶R ( I , T )DT +DI¶T I = I¶I T =T00DT
DI= R0 (1 + a I+ bI )T0I0

Normal, Rn

RSuperconducting

T18

TES Development Status & Plan at PMO

1. THz TES⎯ Pixel number：8x8⎯ Sensitivity：BGLP

2. Optical/NIR TES⎯ QE: >90%
⎯ Energy resolution: <0.4eV⎯ Counting photons: >10
3. X-Ray TES Micro-Calorimeter⎯ Band: 0.3-7/12keV⎯ Energy resolution: <5eV
⎯ Pixel number: >1k19

KID – from THz 2D/3D to Optical Imaging
1k pixel KID chip
Superconducting
coupler (capacitor）

Antenna

Physics:
Generation, recombination &fluctuation of quasiparticles
Image credit: TUDelft⎯ Single-layer film process
Superconductinginductor⎯ High FDM ratio
20

First KID Camera Developed in China
1024 Al MKIDs & micro-lens array

10-16

measured NEP @ 1.4 THz
Photon noise
G-R noise+Photon noise

noise

10-17

10-19

oton

G-R noise

10-18

phcouplertwin-slot
antenna

CPW feedline

1/4-l resonator

NEP (W/Hz0.5)

J. Li et al, JLTP 184 (2016);
Q. Shi et al, Sci. China 65 (2022)

10-4

10-2

100

102

104

Radiation power (fW)21

THz Spatial-Spectral 3D Imaging (LIM) with KID

22

Device Fabrication Facility at PMOSIS
10 µm

HEB
KID

TES
23

Thank You !

24