摘要 |
Jitter and waveform are improved by reducing the wavelength spectrum width of a laser beam pulse. In a laser pulse generating apparatus according to the present invention, a semiconductor laser device, a polarization maintaining optical fiber, an optical reflection filter having bandpass characteristics using an FBG whose passband can be changed by changing a tension, and an optical isolator are connected via an optical fiber. A driving circuit drives the semiconductor laser device to generate a pulse. The optical reflection filter performs filtering by transmitting a specific component of the wavelength spectrum of the pulse, reflects a portion of the optical power, and outputs the remaining optical power except the reflected portion to the outside via the optical isolator. The reflected pulse is fed back to the semiconductor laser device to thereby reduce the wavelength spectrum width of the laser beam, and improve the jitter and waveform.
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