He is a Co-I for NASA supported GUSTO balloon observatory. He is a co-chair of the Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy conference, SPIE Astronomical Telescopes and Instrumentation, and also the international scientific advisory committee member of The 29 th International Symposium on Space Terahertz Technology, ISSTT 2018, Pasadena, USA. Gao has published so far more than 250 papers in the following areas: THz phase gratings, wavefront, superconducting hot electron bolometer mixers and arrays, THz quantum cascade lasers, TES for FIR and X-ray, FDM, space instrumentations, KIDs, SIS mixers, nanostructures and physics,