TY - GEN
T1 - Multiple terahertz beams based on a Fourier grating and a quantum cascade laser
AU - Gan, Y.
AU - Mirzaei, B.
AU - Silva, J. R.G.
AU - Khalatpour, A.
AU - Hu, Qing
AU - Groppi, C.
AU - Siles, J. V.
AU - Van Der Tak, F. F.S.
AU - Gao, J. R.
PY - 2020
Y1 - 2020
N2 - Large heterodyne receiver arrays (~100 pixel) allow astronomical instrumentations mapping more area within limited space mission lifetime. One challenge is to generate multiple local oscillator (LO) beams. Here, We succeeded in generating 81 beams at 3.86 THz by combining a reflective, metallic Fourier grating with an unidirectional antenna coupled 3rd-order distributed feedback (DFB) quantum cascade laser (QCL). We have measured the diffracted 81 beams by scanning a single pyroelectric detector at a plane, which is in the far field for the diffraction beams. The measured output beam pattern agrees well with a simulated result from COMSOL Multiphysics with respect to the angular distribution and power distribution among the 81 beams. We also derived the diffraction efficiency to be 94\pm 3\%, which is very close to what was simulated for a manufactured Fourier grating (97%). For an array of equal superconducting hot electron bolometer mixers, 64 out of 81 beams can pump the HEB mixers with similar power, resulting in receiver sensitivities within 10%. Such a combination of a Fourier grating and a QCL can create an LO with 100 beams or more, enabling a new generation of large heterodyne arrays for astronomical instrumentation. This paper is essentially a copy of our paper in Optics Express.
AB - Large heterodyne receiver arrays (~100 pixel) allow astronomical instrumentations mapping more area within limited space mission lifetime. One challenge is to generate multiple local oscillator (LO) beams. Here, We succeeded in generating 81 beams at 3.86 THz by combining a reflective, metallic Fourier grating with an unidirectional antenna coupled 3rd-order distributed feedback (DFB) quantum cascade laser (QCL). We have measured the diffracted 81 beams by scanning a single pyroelectric detector at a plane, which is in the far field for the diffraction beams. The measured output beam pattern agrees well with a simulated result from COMSOL Multiphysics with respect to the angular distribution and power distribution among the 81 beams. We also derived the diffraction efficiency to be 94\pm 3\%, which is very close to what was simulated for a manufactured Fourier grating (97%). For an array of equal superconducting hot electron bolometer mixers, 64 out of 81 beams can pump the HEB mixers with similar power, resulting in receiver sensitivities within 10%. Such a combination of a Fourier grating and a QCL can create an LO with 100 beams or more, enabling a new generation of large heterodyne arrays for astronomical instrumentation. This paper is essentially a copy of our paper in Optics Express.
UR - http://www.scopus.com/inward/record.url?scp=85099456944&partnerID=8YFLogxK
U2 - 10.1109/UCMMT49983.2020.9296021
DO - 10.1109/UCMMT49983.2020.9296021
M3 - Conference contribution
AN - SCOPUS:85099456944
T3 - 2020 13th UK-Europe-China Workshop on Millimetre-Waves and Terahertz Technologies, UCMMT 2020 - Proceedings
BT - 2020 13th UK-Europe-China Workshop on Millimetre-Waves and Terahertz Technologies, UCMMT 2020 - Proceedings
PB - IEEE
T2 - 13th UK-Europe-China Workshop on Millimetre-Waves and Terahertz Technologies, UCMMT 2020
Y2 - 29 August 2020 through 1 September 2020
ER -