Application of micro-pattern gaseous detectors to photon detection has been widely investigated over the past decades. In this talk, I will present a double micro-mesh (DMM) gaseous structure developed with a thermal bonding technique for this application. A detector prototype has been built with this structure and showed excellent performance for detecting single photons in various tests with X-rays and UV laser light. The gain of the gaseous structure can reach up to 10^6 for single electrons while maintaining a very low ion-backflow ratio down to 0.05%. The structure can maintain a stable gain of > 7×10^4 with a good energy resolution of 19% (FWHM) for 5.9 keV X-rays. The DMM has good potential to serve as photon detector in Cherenkov light detection, as well as for other applications, e.g. TPC readout, that require a very low level of ion backflow. The thermal bonding technique used in the development of DMM, including its advantages over conventional Micromegas fabrication methods, will also be briefly introduced.