Experimental Study On The Pulse Pump Telecom Band For All-fiber Source Of Correlated Photon Pairs

Correlated photon pairs is an important resource to reveal the fundamental laws of quantum mechanics and quantum information processing, the quantum correlated photon source in1550nm based on optical fiber communication band drew attention for it’s small size, easy to implement, and fully compatible with existing fiber-optic systems, the principle of which is with pulse laser pumping the dispersion-shifted fiber, the correlated photons were generated by spontaneous four-wave mixing. High-quality and compact pulsed fiber laser is a key factor of correlated photon sources, so an all-fiber mode-locked pulse laser was set up in this paper, with it’s applicability in the correlated photon source was studied.In the thesis, a pulsed erbium-doped fiber pulse laser with single polarization controller was built based on the nonlinear polarization rotation, which output is stable passively mode-locked pulse train, and a variety of harmonic mode-locked phenomenon was observed. The center wavelength of the laser are located at1533.7nm and1558.7nm, with the repetition rate20.21MHz, maximum output power8.5mW, the measured pulse width is528fs, the time-bandwidth product is0.47, which is about1.1times high of the Gaussian pulse Fourier transform limit. We measured its single-channel photon counting rate and coincidence count pumped by this laser, the laser’s pulse contrast ratio was also measured, all measurement showed the well applicability of the laser in the quantum correlated source.The main contents of the thesis are as follows:First, introduce details of fiber laser, including the basic structure, the principles, characteristic and classification, explaining the characteristic of the erbium-doped fiber, and the source’s demands for pump light; then a single polarization controller mode-locked pulse laser was built based on the top theory, and studied its output characteristic; finally, measured the single-channel photon count rate and coincidence counting rate of the correlated photons, and did theoretical analysis and experimental measurement in the pulse contrast of the laser, which proved that the laser provided an effective pump for the quantum correlated source.