Md. Najmul Islam

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When pulse pairs copropagate in a fiber, each pulse chirps the other through cross-phase modulation (XPM). In particular, XPM causes spectral broadening of signal pulses during Raman or parametric optical pulse amplification. We have studied XPM experimentally in the fiber Raman amplification soliton laser. We show that experimentally observed spectra can(More)
Genetic diversity of two wild Kalibaus, Labeo calbasu populations and one hatchery stock was studied using random amplified polymorphic DNA (RAPD) method. The three 10–mer random primers (OPA01, OPB02 and OPC03) yielded a total of 26 reproducible and consistently scorable RAPD bands of which 15 (57.69%) were considered as polymorphic (P95) indicating a high(More)
By propagating 500-fs pulses through 2.5 m of standard fiber followed by 2 m of dispersion-shifted fiber, we generated >200 nm of spectral continuum between 1430 and 1630 nm, which is flat to less than ?0.5 dB over more than 60 nm. Pulses obtained by filtering the continuum show no increase in timing jitter over the source laser and are pedestal free to >28(More)
We observe all-optical, ultrafast switching at an energy of 55 pJ in a fiber nonlinear-optical loop mirror. The entire 310-fsec soliton waveform switches with 90% peak transmission. The soliton self-frequency shift lowers the peak transmission and splits the output pulse at higher powers, in agreement with numerical simulations.
We show experimentally the trapping of orthogonally polarized solitons in birefringent optical fibers with polarization dispersions as high as 90 psec/km. Solitons along two axes of a fiber compensate for the polarization dispersion by shifting their frequencies, and we observe frequency splitting up to 1.03 THz for a polarization dispersion of 80 psec/km.(More)
Bandwidth and peak efficiency are enhanced for wavelength conversion based on induced modulation instability by use of dispersion-shifted fiber in which the nonlinearity (n(2)/A(eff)) is enhanced by a factor of ~4.5 over that of conventional dispersion-shifted fiber. We experimentally obtain a peak conversion efficiency as high as 28 dB over a 40-nm(More)
Ultrafast all-optical soliton-trapping logic gates, including an inverter, exclusive OR, and AND, are experimentally demonstrated in birefringent fibers. The soliton-trapping logic gates are three terminal devices with orthogonally polarized inputs, phase-insensitive nonlinear operation, and switching energies of ~42 pJ. Using a 0.2-THz bandpass filter, the(More)
We used power-spectrum techniques to measure both amplitude noise and timing jitter of two femtosecond colorcenter lasers in the near infrared: a passively mode-locked laser and an additive-pulse mode-locked laser. The cw pumped passively mode-locked color-center laser showed better noise performance than the feedback-controlled, much more complex(More)
With sufficient Raman gain to compensate exactly for net fiber energy loss, we have demonstrated distortionless propagation of 10-psec FWHM fundamental (N = 1) soliton pulses (lambda = 1.56 microm) over a 10-km length of single-mode fiber. The implications of this experiment for development of an all-optical, high-bit-rate, long-distance telecommunications(More)
We synchronize two passively mode-locked erbium-doped fiber lasers by adjusting only the cavity length to correct both the repetition rate and the phase. The interlaser jitter is less than 6 ps (1.3 times the pulse width) and is extracted from the cross correlation of the two lasers. The lock can be maintained for extended periods of time. These results are(More)