PURPOSE: To output a laser light for a laser knife over a wide range of electric power by a method wherein a photo attenuator or a photo energy controller is detachably provided at the light incidence port of a photo detector, and then a control signal, etc. are fed back to the attenuator, etc. by comparing the output of a photosensor with the reference voltage.
CONSTITUTION: The laser light I0 is oscillated from a carbonic acid gas discharge tube 1 under a discharge current controller 3 by a high voltage generated in a high voltage generator 2. This light I0 is split into a working light I1 and a monitor light I2 by a partial transmitting mirror 4. The light I1 is condensed through an optical system to irradiation on affected parts, etc., thus serving to cut open the organic tissue or join vessels. On the other hand, the light I2 is detected by the photosensor 5; when its energy is relatively large, the photo attenuator or the energy controller 6 is detachably placed at the incidence port of the photosensor 5. Then, a deviation amplifier 7 feeding the control signal back to the discharge current controller 3 by comparing the output of the photosensor 5 with the fixed reference voltage (e) is provided, and then the photo output of the oscillating part is controlled according to the control signal.
OOTA YOUSUKE
HIRAMA MASAYUKI
