Vishwatosh Mishra

Sub-Wavelength Dual Capillaries-Assisted Chalcogenide Optical Fibers: Unusual Modal Properties in Mid-IR (2–5 μ m) Spectral Range

In this study, we apply the concept of sub-wavelength light confinement to achieve flat effective mode area (Aeff) characteristics over a wide wavelength range of 1400 nm in nano-sized dual capillary assisted chalcogenide core optical fibers. An unusual spectral behavior of Aeff is observed where the effective mode area increases, remains constant for a wide bandwidth, decreases and again increases with the increase in wavelength. The spectral region, in which this behavior is observed, can be tuned by varying the structural parameters of the fiber. Additionally, we noticed that the fiber exhibits four zero dispersion wavelengths for a particular polarization which suggests that sub-wavelength light localization can be an alternative solution for the dispersion engineering in order to attain multiple zero dispersion wavelengths. The fabrication tolerance of the dispersion profile has been found to fall within the current fabrication accuracies achievable. We believe that our findings might be useful in different applications such as light-matter interaction and spatial soliton propagation.

Stability analysis and bandwidth estimation of free-carrier driven Kerr frequency-comb

Free-carrier dispersion-led nonlinear cavity detuning is observed through the reverse Kerr-tilt of the resonant-peaks of steady-state solutions of Lugiato-Lefever equation. Effects of nonlinear losses on the gain-spectrum and the gain-bandwidth of modulation-instability are also studied.

Pulse-Splitting and Pulse-Locking Dynamics in Multi-Mode Optical Fibers

We study the multimode propagation dynamics in a fiber, observe the pulse-splitting and pulse-locking marked by a significant portion of the LP01-mode pulse moving together with the LP02-mode pulse despite of significant walk-off between them.

Pulse Width and Temperature-Dependent Supercontinuum Generation in Silicon Nitride Dual-Slot Waveguide with Ultralow Dispersion

Silicon nitride dual-vertical slot waveguide is proposed to achieve ultra-low dispersion possessing flatness of 0.01 psnm−2km−1 along with four zero dispersion wavelengths. The effect of pulse width and temperature on octave spanning supercontinuum is studied numerically.

Dynamics of Phase Matching Characteristics of Bismuth-Oxide based Birefringent Photonic Crystal Fiber Parametric Amplifier

The dispersion and phase-matching topologies in view of parametric wavelength generation from near IR to mid-IR in bismuth-oxide photonic crystal fiber have been reported. Fiber exhibits two zero dispersion wavelengths and birefringence of 10-4.