| 摘要 |
<p>The apparatus consists of a laser generator (1), beam divider (2), shutter, focusing lens (4) placed behind the shutter, in whose focal point there is the optical fibre (5) input, and control unit (7). The shutter is mechanical-optical and is made up of a dichroic optical divider (3), which is offset and tilted in relation to the incident laser radiation. On the incident side of the generated laser radiation there are at least two alternating areas with small and large reflectivity for the frequency of that laser radiation and on the reverse side of the dichroic optical divider (3) there are, equal in terms of position and dimensions, at least two alternating areas with small and large reflectivity for laser protoplasm radiation generated at the end of the optical fibre (5) at the point of interaction during laser fragmentation. A spectrally selective measurement system (6) is inserted into the path of the reflected laser protoplasm radiation from the dichroic optical divider (3) beam; it consists of minimally two branches formed by the beam divider (61), a narrowband filter (62), detector (63) and measurement channel (64). Each filter (62) is determined for a different spectral line. The output from the measurement channel (64) is connected to the control inputs of the control unit (7), whose first output is connected with the input of the laser generator (1) and the second output is connected through the control circuits (12) with a power unit (13), whose shaft is connected to the dichroic optical divider (3). The beam divider (2) is located between the laser generator (1) and shutter on the axis of output of beams of generated laser radiation. A detector (8) is inserted into the path of the reflected laser protoplasm radiation, its output connected through the reference channel (9) to the reference input of the control unit (7).<IMAGE></p> |
