Coherence properties of the supercontinuum generated in anomalous dispersion region of photonic crystal fibers

Abstract

We numerically calculated the coherence properties of the supercontinuum based on the definition of complex degree of mutual coherence, and obtained the spectral broadening of the pump pulse and the coherence properties of the generated supercontinuum under different pump powers. The results showed that the dominant underlying mechanisms of the spectral broadening are soliton self-frequency shift and dispersive wave generation when the pump wavelength located in the anomalous dispersion region of photonic crystal fiber. While the coherence properties are affected by the modulation instability which amplifies the stochastic noise of the pump pulse, thus the generated frequency components have stochastic phases and amplitudes, which induces the degradation of the coherence of the supercontinuum. The gain of modulation instability increases with the increasing of the pump power, and the effect of the noise on the supercontinuum will become greater which degrades the coherence properties. Low pump power is required to obtain high coherent supercontinuum, and suitable pump power should be adjusted to get wide bandwidth and high coherent supercontinuum.

Field test of supercontinuum laser in atmospheric turbulence

“…Laser transmission in the atmosphere is mainly affected by atmospheric attenuation, turbulence and background radiation [1][2][3] , where atmospheric attenuation causes extinction effects and turbulence causes random fluctuations in laser phase. In recent years, researchers have found that partially coherent lasers can reduce the effect of turbulence on transmission 4,5 , while the unique characteristics of supercontinuum with good spatial coherence and low temporal coherence are well suited for atmospheric transmission studies 6 . The supercontinuum laser also has the characteristics of wide spectrum, high brightness, good directionality [7][8][9] , which possess prevailing advantages in atmospheric transmission research [10][11][12] .…”

High stability supercontinuum generation in lead silicate SF57 photonic crystal fibers

“…The use of high index PCF for SC generation is cuttingedge research in the field of photonics. [6,7] Many unusual properties can be achieved, including the range of transmission extending to mid-infrared, [8] the zero dispersion wavelength (ZDW) up to 2.0 µm, [9] and the ultraflat SC generation. [10] SC generation provides a broadband optical source for the optical frequency metrology, [11] frequency comb generation, [12] and optical coherence tomography.…”

Pulse collapse and blue-shifted enhanced supercontinuum in a photonic crystal fiber

“…[5][6][7][8][9] Since the magnitude of the soliton self-frequency shift inversely increases with the increasing pulse duration, the soliton self-frequency shift of the solitons created after fission leads to a red spectral broadening in the PCF with anomalous group velocity dispersion. [10][11][12][13][14] At the same time, the dispersive wave generation extends the spectrum into the visible and the ultraviolet spectral ranges where the group velocity dispersion is normal.…”