An optical pulses emitter includes a first and a second Fabry-Perot laser diodes. The first and second laser diodes have a first and second working optical wavelength band respectively, and the first and second working wavelength bands has at least an overlapped wavelength band. The emitter also includes a signal source in connection with the first laser diode such that a plurality of optical pulses over the first working optical wavelength band is generated and an optical filter for filtering the optical pulses so as to output a plurality of optical pulses primarily of a desired optical wavelength, which falls into the overlapped wavelength band. The emitter further includes an optical amplifier along an optical path between the first and second Fabry-Perot laser diodes for amplifying the optical signals passing therethrough. The optical pulses primarily of the desired optical wavelength are injected into the second laser diode, and the second laser diode, stimulated by the injected optical signals, outputs optical pulses primarily of the desired optical wavelength.