Assoc. Prof. Guan's research interests include the next generation of high integration, large bandwidth nanophotonic information devices, enhanced spectroscopy. The main academic research results are summarized as follows: 1) a series of achievements have been achieved around the controllable preparation and cascade of subwavelength on-chip optical information devices, such as light source, waveguide and detector. For example, a photothermoelectric on-chip photodetector with plasmon modulation has been realized in silicon for the first time. The photothermoelectric effect caused by steady-state hot carrier system with temperature higher than the lattice system was studied in detail. The controllable fabrication of subwavelength, high-performance plasmonic waveguide; 2) The near-field optical scanning microscope system with metallic nanowire tip was built, and we solved the problems of fabrication of metallic nanowire near-field scanning probe and the weak signal measurement; 3) the real-time Raman detection of molecules in microfluidic environment was realized, which can be used for the early diagnosis of food and environmental safety and diseases with on-chip integrated chip SERS (LOC SERS); 4) the nanofabrication of metasurface information devices. He has published 30 papers, with 11 top journals published as first or correspondence (co-) author in recent three years.