公开(公告)号：US5015099A

公开(公告)日：1991-05-14

申请号：US492784

申请日：1990-03-12

申请人： Haruo Nagai ,  Kiyoji Uehara ,  Masafumi Aizawa

发明人： Haruo Nagai ,  Kiyoji Uehara ,  Masafumi Aizawa

IPC分类号： G01N21/39

CPC分类号： G01N21/39 ,  G01N2021/394

摘要： A light source has a tunable wavelength single mode semiconductor laser. The laser outputs a single mode laser beam having a wavelength tuned in accordance with a drive current and emits, for an object to be detected, at least a first laser beam having a first wavelength which is absorbed by a gas to be detected and a second laser beam having a second wavelength which is not absorbed by the gas to be detected. A controller switches the drive current having a predetermined value corresponding to the first or second wavelength at a predetermined period and supplies the drive current to the laser and controls the drive current having the predetermined value corresponding to the first or second wavelengths so that the first or second laser beams are alternately output from the laser with substantially the same power while the first and second wavelengths are maintained. A light-receiving unit receives first and second response light components generated when the first and second laser beams emitted alternately from the laser are incident on the object to be detected and outputs electrical signals corresponding to received light amounts of the first and second response light components. A signal processor receives the electrical signals from the light-receiving unit and processes the presence/absence of gas detection in accordance with a difference between the received light amounts of the first and second response light components.

摘要翻译： 光源具有可调波长单模半导体激光器。 激光器输出具有根据驱动电流调谐的波长的单模激光束，并且对于被检测物体发射至少一个具有被待检测气体吸收的第一波长的第一激光束和第二激光束 具有不被待检测气体吸收的第二波长的激光束。 控制器以预定周期切换具有对应于第一或第二波长的预定值的驱动电流，并将驱动电流提供给激光器，并控制具有与第一或第二波长对应的预定值的驱动电流，使得第一或第二波长 在保持第一和第二波长的同时，第二激光束以大致相同的功率从激光器交替地输出。 光接收单元接收当从激光器交替地发射的第一和第二激光束入射到被检测物体时产生的第一和第二响应光分量，并输出与第一和第二响应光分量的接收光量相对应的电信号 。 信号处理器接收来自光接收单元的电信号，并且根据第一和第二响应光分量的接收光量之间的差来处理气体检测的存在/不存在。