Patent ID: 9316531
Filing Date: 2016-04-19
CPC Classification: G01J,H01S

Claim Text:
1. A signs-of-deterioration detector for a semiconductor laser comprising: a first light receiving section that acquires first information relating to an optical output of the semiconductor laser at a first time point and second information relating to an optical output of the semiconductor laser at a second time point, later than the first time point; a second light receiving section that acquires third information relating to an intensity distribution of an emission pattern of the semiconductor laser below a lasing threshold of the semiconductor laser at a third time point which is different from the first time point and is earlier than the second time point and fourth information relating to an intensity distribution of an emission pattern of the semiconductor laser below a lasing threshold of the semiconductor laser at a fourth time point which is different from the second time point and is later than the first time point and the third time point; a holding section that holds the first information acquired by the first light receiving section and the third information acquired by the second light receiving section; a deciding section that decides presence or absence of signs of decrease of the optical output of the semiconductor laser, by comparing the first information held by the holding section with the second information acquired by the first light receiving section and also comparing the third information held by the holding section with the fourth information acquired by the second light receiving section; and an outputting section that outputs a signal from the deciding section.