MEASURING DEVICE FOR WAVELENGTH DISPERSION

摘要

PURPOSE:To accurately measure wavelength dispersion by using an injecting semiconductor laser oscillated in a single vertical mode to inject output light into a modulated semiconductor laser to be injected and unify the oscillation spectrum of the injecting semiconductor laser. CONSTITUTION:An injecting semiconductor laser 3 is driven by a DC current source 1a and an output from a low-frequency pulse generator 2 and the oscillation vertical mode of the laser 3 is controlled by a Peltier element 4a. The optical output of the laser 3 is injected to a semiconductor laser 6 to be injected through lenses 5a, 5b. The laser 6 is modulated by a DC current source 1b and an output from a pulse generator 7. An output from the laser 6 is made incident to one end of an optical fiber 8 to be measured and output light from the other end of the fiber 8 is received by a photodetector 9. The output of the photodetector 9 is inputted to a sampling scope 11 through an amplifier 10 and its waveform is observed. Thus optical pulses to be make incident to the optical fiber 8 are outputted alternately as single different wavelengths which are comparatively close to each other, making it possible to measure accurate wavelength dispersion.