Print Email Facebook Twitter 8-beam local oscillator array at 4.7 THz generated by a phase grating and a quantum cascade laser Title 8-beam local oscillator array at 4.7 THz generated by a phase grating and a quantum cascade laser Author Mirzaei, B. (TU Delft QN/Gao Lab; Kavli institute of nanoscience Delft) Silva, J. R.G. (SRON Netherlands Institute for Space Research) Hayton, D (SRON Netherlands Institute for Space Research) Groppi, C (Arizona State University) Kao, T. Y. (Massachusetts Institute of Technology) Hu, Q. (Massachusetts Institute of Technology) Reno, John L. (Sandia National Laboratories, New Mexico) Gao, J.R. (TU Delft QN/Gao Lab; SRON Netherlands Institute for Space Research; Kavli institute of nanoscience Delft) Date 2017-11-27 Abstract We present an 8-beam local oscillator (LO) for the astronomically significant [OI] line at 4.7 THz. The beams are generated using a quantum cascade laser (QCL) in combination with a Fourier phase grating. The grating is fully characterized using a third order distributed feedback (DFB) QCL with a single mode emission at 4.7 THz as the input. The measured diffraction efficiency of 74.3% is in an excellent agreement with the calculated result of 75.4% using a 3D simulation. We show that the power distribution among the diffracted beams is uniform enough for pumping an array receiver. To validate the grating bandwidth, we apply a far-infrared (FIR) gas laser emission at 5.3 THz as the input and find a very similar performance in terms of efficiency, power distribution, and spatial configuration of the diffracted beams. Both results represent the highest operating frequencies of THz phase gratings reported in the literature. By injecting one of the eight diffracted 4.7 THz beams into a superconducting hot electron bolometer (HEB) mixer, we find that the coupled power, taking the optical loss into account, is in consistency with the QCL power value. Subject OA-Fund TU Delft To reference this document use: http://resolver.tudelft.nl/uuid:86b9810f-559f-44b8-90a6-e9d741c69fa4 DOI https://doi.org/10.1364/OE.25.029587 ISSN 1094-4087 Source Optics Express, 25 (24), 29587-29596 Part of collection Institutional Repository Document type journal article Rights © 2017 B. Mirzaei, J. R.G. Silva, D Hayton, C Groppi, T. Y. Kao, Q. Hu, John L. Reno, J.R. Gao Files PDF oe_25_24_29587.pdf 3.69 MB Close viewer /islandora/object/uuid:86b9810f-559f-44b8-90a6-e9d741c69fa4/datastream/OBJ/view