| 摘要 |
<p>An optical measurement apparatus for measuring spectrum in a gas cell, the optical measurement apparatus comprises: a light source S with a predetermined wavelength range; a first mirror M1 which reflects the light emitted from the source to a long path gas cell1; and a second mirror M2 which reflects the light outputted from the long path gas cell to a sensor D. An optical element 21, 22 which has a bifocal property is positioned in the light path between the light source S and the sensor D. The bifocal property of the optical element gives the optical element different focal lengths as measured in two directions perpendicular to the light path. The first and second mirrors M1, M2 may be mounted with the bifocal optical element 21, 22. A movement means may move the first and second mirrors away from the light path between the light source and sensor (L, fig. 4), and thus disposing a short light path gas cell 2 to the light beam from the source to sensor.</p> |
