Qian Li, K. Senthilnathan, K. Nakkeeran, and P. K. A. Wai, "Nearly chirp- and pedestal-free pulse compression in nonlinear fiber Bragg gratings," J. Opt. Soc. Am. B 26, 432-443 (2009)
We demonstrate almost chirp- and pedestal-free optical pulse compression in a nonlinear fiber Bragg grating with exponentially decreasing dispersion. The exponential dispersion profile can be well-approximated by a few gratings with different constant dispersions. The required number of sections is proportional to the compression ratio, but inversely proportional to the initial chirp value. We propose a compact pulse compression scheme, which consists of a linear and nonlinear grating, to effectively compress both hyperbolic secant and Gaussian shaped pulses. Nearly transform-limited pulses with a negligibly small pedestal can be achieved.
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
You do not have subscription access to this journal. Figure files are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
You do not have subscription access to this journal. Article tables are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
You do not have subscription access to this journal. Equations are available to subscribers only. You may subscribe either as an Optica member, or as an authorized user of your institution.
is the normalized chirp coefficient of the chirped hyperbolic secant or Gaussian input pulse. The normalized chirp coefficients after the linear FBG are determind by fitting the phase of the pulse using , where is the pulse width parameter of the hyperbolic secant or Gaussian pulse. Similarly, the chirp coefficient of the compressed pulse, , is determined by fitting the phase of the pulse using , where is the pulse width parameter of the compressed pulse.
Table 4
Comparison of the Pedestal Generated for Different Values of the a
Ratio
Change of
Change of Peak Power
1
6.49%
6.49%
1.2
1.47%
1.47%
0.0935%
1.6
1%
1%
1.8
2.42%
2.38%
2
3.69%
3.68%
and are the initial dispersion and nonlinear lengths, respectively, of the ratio. The different values of are obtained by either changing the initial dispersion value of NFBG or changing the peak power of the initial pulse. Different lengths of NFBG are used to achieve the same FWHM of the final compressed pulse.
Tables (4)
Table 1
Comparison Between Different Pulse Compression Schemes
Large Compression Ratio
Pedestal-Free
Chirp-Free– Almost Chirp-Free
Avoid Wave Breaking at High Powers
Short Length
Higher-order soliton compression
√
Adiabatic pulse compression in fibers
√
Adiabatic pulse compression in NFBG
√
√
Self-similar pulse compression in fibers
√
√
√
√
Self-similar pulse compression in NFBG
√
√
√
√
√
Table 2
Values of the Constants in Eq. (12) for Different Choices of the Reduction Methods and Ansatz
is the normalized chirp coefficient of the chirped hyperbolic secant or Gaussian input pulse. The normalized chirp coefficients after the linear FBG are determind by fitting the phase of the pulse using , where is the pulse width parameter of the hyperbolic secant or Gaussian pulse. Similarly, the chirp coefficient of the compressed pulse, , is determined by fitting the phase of the pulse using , where is the pulse width parameter of the compressed pulse.
Table 4
Comparison of the Pedestal Generated for Different Values of the a
Ratio
Change of
Change of Peak Power
1
6.49%
6.49%
1.2
1.47%
1.47%
0.0935%
1.6
1%
1%
1.8
2.42%
2.38%
2
3.69%
3.68%
and are the initial dispersion and nonlinear lengths, respectively, of the ratio. The different values of are obtained by either changing the initial dispersion value of NFBG or changing the peak power of the initial pulse. Different lengths of NFBG are used to achieve the same FWHM of the final compressed pulse.