Font Size: a A A

Research On Utra-wideband Supercontinuum Light Source Based On 1?m/1.5?m Pulsed Fiber Laser

Posted on:2018-09-16Degree:MasterType:Thesis
Country:ChinaCandidate:J YuFull Text:PDF
GTID:2348330536956151Subject:Optics
Abstract/Summary:PDF Full Text Request
Owing to the unique features of wide spectral range,high spectral energy density,etc,supercontinuum laser sources have been widely applied in many fields such as optic coherence tomography,spectrum frequency measurement,Fourier transform infrared spectrometer,fingerprint,wavelength division multiplexing system and laser radar.The researches of ultra-wideband supercontinuum laser source,not only have important academic significance,but also have practical significance.The main contents of our research on this subject are shown as following:1.The background of the fiber lasers was briefly introduced firstly,and then the feature of double-cladding Er/Yb co-doped fiber,the development of dual-waveband fiber laser and supercontinuum laser source was also illustrated.2.Using two independent 1 ?m and 1.5 ?m fiber preamplifiers as the seed sousces,through a master oscillator power amplifier structure,of which the main amplifier adopted a large mode area Er/Yb co-doped fiber as the gain medium,the dual-band pulses were amplified at the same time.To optimize the performance of this dual-band laser source with comparable output powers,the influence of the length of the large mode area Er/Yb co-doped fiber,the pulse repetition ratio of the 1.5 ?m signal,the ratio between the two seed powers and the wavelength of the 1 ?m seed signal were experimentally investigated.Through optimizing the conditions above,we have demonstrated a high-power single-mode dual-band pulsed fiber laser with output powers of 10.6 W and 25.8 W at 1 ?m and 1.5 ?m,respectively.The slope efficiency was 20.3 % and the optical conversion efficiency was 20.5 %.3.Using a 1 ?m/1.5 ?m dual-band synchronized picosecond pulsed fiber laser based on nonlinear polarization rotation and synchronous pumping as the seed source,through adjusting the delay line of the 1.5 ?m output,the dual-band pulses were synchronized at the output of the preamplifiers.And then the synchronized pulses were amplified in the large mode area Er/Yb co-doped fiber amplifier.The experimental results showed that when the dual-band laser signal were synchronous pulses,they absorbed the pump light synchronously in the Er/Yb co-doped fiber and were amplified synchronously.However,most energy the Yb3+ absorbed were transferred to the Er3+,and the Er3+ also absorbed the 1 ?m laser energy for its own amplification.Under the pump power of 125 W,we obtained dual-band pulsed output of 6.6 W and 17.7 W at the 1 ?m and 1.5 ?m,respectively.And the peak powers were 6.3 k W and 5.9 k W,respectively.4.Research on pumping the cascaded photonic crystal fiber and highly nonlinear dispersion-shifted fiber with the high-power 1 ?m/1.5 ?m dual-band pulsed fiber laser.Firstly,the supercontinua were generated in a photonic crystal fiber with a length of 1.4 m,4 m,and 8 m,respectively.It showed that the length of 1.4 m achieved the widest spectrum(500-2500 nm)and the highest output power(10.7 W).And then the supercontinuua were generated in a cascaded 1.4-m photonic crystal fiber and highly nonlinear dispersion-shifted fiber with different lengths.To extend the long wavelength edge of the generated supercontinuua,the length of 0.2 m was the most suitable.Pumping with 18.8 W dual-band laser,the power of the supercontinuum generated in the cascaded 1.4-m photonic crystal fiber and 0.2-m highly nonlinear dispersion-shifted fiber was 9.01 W,and the spectrum extended from 500 nm to 3000 nm,covering the visible to mid-infrared waveband.Then,pumping the cascaded photonic crystal fiber and highly nonlinear dispersion-shifted fiber with the high-power dual-band synchronous pulsed fiber laser was investigated.Pumping with 15.2 W dual-band synchronous pulsed fiber laser,the power of the supercontinuum generated in the cascaded 10-m photonic crystal fiber and 0.5-m highly nonlinear dispersion-shifted fiber was 4.5 W,and the spectrum extended from 500 nm to 2760 nm,covering the visible to mid-infrared waveband.
Keywords/Search Tags:Dual-band Pulsed Fiber Laser, Synchronous Pulses, Master Oscillator Power Amplifier, Erbium Yitterbium Co-doped Fiber, Supercontinuum
PDF Full Text Request
Related items