摘要:
According to one embodiment, in one embodiment of the invention, a laser drive circuit is provided with a first current source, a second drive current source, and a third current source. The control section selectively obtains a plurality of laser light use mode of controlling the from first to third current sources to use pulse laser light accompanying relaxation oscillation, and a complex laser light use mode of using laser light where laser pulses are combined, whose starting end has an abrupt impulse change portion caused by relaxation oscillation and whose intermediate section is a flat portion with a fixed intensity.
摘要:
According to one embodiment, a drive control apparatus of a semiconductor laser includes a driving circuit which drives the semiconductor laser by applying pulses transiting from bias current to peak current to the semiconductor laser as laser driving current that causes relaxation oscillation of emission light intensity of the semiconductor laser, and a control circuit which controls the bias current such that the bias current has a predetermined ratio limiting fluctuation of a leading peak value of the relaxation oscillation occurring for each application of pulses relative to threshold current of the semiconductor laser. The control circuit changes the bias current to maintain the predetermined ratio relative to fluctuation of the threshold current.
摘要:
According to one embodiment, a laser drive circuit includes a photodetector which receives part of laser light emitted from a laser element to a recording medium independently of reflection laser light reflected by the recording medium, and outputs an output corresponding to the strength thereof, an integration circuit which integrates the output from the photodetector for a predetermined time, and a setting circuit which sets the intensity of a laser drive current supplied to the laser element on the basis of the output from the integration circuit.
摘要:
A fiber laser device contains a first optical fiber of a double-clad type in which optical resonance of an infrared laser light takes place inside a core with Pr3+and Yb3+added thereto to generate a light of a wavelength of about 630 nm, a second optical fiber of a double-clad type in which optical resonance of an infrared laser light takes place inside a core with Pr3+and Yb3+added thereto to generate a light of a wavelength of about 690 nm, and a third optical fiber in which optical resonance of the lights from the first and second optical fibers takes place inside a core with Tm3+added thereto to generate a light of a wavelength of about 450 nm, and the core diameter of the third optical fiber is made substantially equal to the spot diameters of the lights from the first and second optical fibers.