The invention discloses a
laser radar device for detecting the
atmospheric temperature based on a vibration-rotation Raman spectrum. After
laser is emitted from a
laser device, the
light beam can be amplified and the
diffusion angle can be compressed by using a
beam expander, and finally the
light beam is emitted to the
atmosphere through a pointing mirror; atmospheric back scattering light is collected by using a
telescope, subsequently passes through an aperture diaphragm, and is finally led into a subsequent optical
system through an
optical fiber; the outgoing light of the
optical fiber is converted into collimated parallel light by using a collimating lens, and is subsequently divided into two paths of signals by using a
beam splitter, one path of the signals passes through a low-order
signal light filtering piece, and the other path of the signals passes through a high-order
signal light filtering piece; the two paths of the
signal light is converted into electric signals through a
photomultiplier I and a
photomultiplier II, and is subsequently acquired and stored by using an acquirer. The strength of a vibration-rotation Raman
spectral line is related to the
atmospheric temperature, and different from a pure rotation Raman
spectral line which is in an interval of 1-3nm from an elastic scattered
ray, a vibration Raman
spectral line is in an interval of 70nm from the elastic scattered
ray, so that interference of an
elastic scattering signal can be effectively avoided by adopting the vibration Raman spectral line.