You specifically ask about laser equipment. I'm not aware of any laser equipment for remote detection, but there are thermal infrared systems that are tuned to identify leaks of various gases. They depend on the IR absorptivity of the gases, so not all gases are suited for detection this way. The systems are appropriate for remote sensing and detection, however. FLIR offers the GasFinder cameras for this. See http://www.flir.com/ogi/content/?id=66693
There are also monitoring systems that can be used, for example in a fixed location such as a stack. These depend on attenuation of a signal that is sent through the stack flow and reflected back to a sensor. Not sure if you'd consider these "laser".