Patent ID: 7755745

Claim:
A coherent Doppler lidar, comprising: a pulse laser an oscillation wavelength of which is controlled by means of injection locking of a seed light output from a master laser; pulse laser beams output from the pulse laser being injected to the atmosphere; and the pulse laser beams receiving a reflected light being the pulse laser beams injected to the atmosphere which are subjected to Doppler shift to detect the Doppler shift based on the reflected light received; wherein the pulse laser is a type in which a laser medium is disposed in a resonator, a pulse light of a predetermined repetition frequency is input to the laser medium as an excitation light, whereby pulse laser oscillation is generated in the resonator to output pulse laser beams from the resonator; the laser medium being a type which has a garnet structure and at least a region having Tm, Ho:YAG ceramics being a material which is prepared by adding at least either of Tm (thulium) and Ho (holmium) as laser active ions to clear YAG (yttrium, aluminum, and garnet) ceramics represented by a chemical formula Y 3 Al 5 O 12 ; the laser medium being excited by the excitation light to output pulse laser beams in a band of a wavelength of 1.9 μm to 2.2 μm; and further, the YAG ceramics are a solid laser made from a polycrystalline substance obtained by aggregating single crystals a size of which is 1 mm or less and; a cooling means for cooling the laser medium is provided.