TRAPPING CAPABILITY OF MICROLENS 2D ARRAY BY ACOUSTIC MODULATION

In this article, the microlens 2D array created in acoustic-optical medium by the ultrasonic wave modulation is proposed. The expression described the refractive index induced by cross-interference of two perpendicular ultrasonic waves is approximately derived. By simulation, the 2D array of the Gradedrefractive index lenses are appeared in the thin layer with certain strain-acoutstic constant and thickness. The  dependence of focal length and the radius of lens, i.e. its numerical aperture (AN) on thickness and strain constant of layer, and ultrasonic wave intensity are simulated and trapping capability of optical tweezer array is discussed

Spectrum Broadening of Supercontinuum Generation by fill Styrene in core of Photonic Crystal Fibers

In this paper, a new photonic crystal fiber with hollow core filled by styrene (PCFS) has been designed for coherent supercontinuum generation. Its main optical characterisitcs are simulated for different lattice microstructure. The PCFS2,0.3 with lattice pitch L=2 mm, filling factor d/L=0.3 and styrene core of diameter of 3.34 mm, owning the flat and anomalous dispersion in the near infrared range from 1.33 mm, lower confinement loss, higher effective refractive index at pump wavelength, and smaller effective mode area is chosen to invetigate the supercontinuum spectrum (SC). The spectrum broadening of SC depending on the fiber’s length, pump duration and pump energy is simulated and discussed in comperison to that obtained in the photonic crystal fibers with hollow core filled with toluene (PCFT2,0.3).

Optimization of Trio-Cavity Raman Laser Pumped by Pulsed Gaussian Beam

In the paper the set of dimensionless rate equations for the pump, Stokes and anti-Stokes powers in the trio-cavity Raman laser pumped by pulsed Gaussian beam is introduced. By numerical Runger-Kuta method, those equations are resolved and the optimal normalized parameters for enhance the output powers are found out

Spectrum Broadening of Supercontinuum Generation by fill Styrene in core of Photonic Crystal Fibers

522-527In this paper, a new photonic crystal fiber with hollow core filled by styrene (PCFS) has been designed for coherent supercontinuum generation. Its main optical characterisitcs are simulated for different lattice microstructure. The PCFS2,0.3 with lattice pitch =2 m, filling factor d/=0.3 and styrene core of diameter of 3.34 m, owning the flat and anomalous dispersion in the near infrared range from 1.33 m, lower confinement loss, higher effective refractive index at pump wavelength, and smaller effective mode area is chosen to invetigate the supercontinuum spectrum (SC). The spectrum broadening of SC depending on the fiber’s length, pump duration and pump energy is simulated and discussed in comperison to that obtained in the photonic crystal fibers with hollow core filled with toluene (PCFT2,0.3)

Ultrasonic-Controled Microlens Arrays in Germanium for Optical Tweezers

The microlens arrays created by ultrasonic waves in acousto-optical material Germanium (Ge) is theoretically proposed. The simulated results show the proposed microlens arrays can be used for optical tweezers arrays to trap an assembly micro-beads. Moreover, with the control by changing of the ultrasonic intensity and frequency, the optical tweezers arrays will act as the dynamical one, which can sieve the beads in (X,Y) plane in the embedding fluid

Dispersion and nonlinearity properties of small solid-core photonic fibers with As2Se3 substrate

Characteristics of As2Se3 photonic crystal fibers (PCFs) with a solid-core and small-core diameter are numerically investigated in the long-wavelength range (from 2 to 10 μm). A full modal analysis and optical properties of designed photonic crystal fibers with lattice constant Λ and filling factor d/Λ are presented in terms of chromatic dispersion, effective refractive index, nonlinear coefficients, and confinement loss. The simulation results show that a high nonlinear coefficient of 4410.303 W–1·km–1 and a low confinement loss of 10−20 dB·km–1 can simultaneously be achieved in the proposed PCFs at a 4.5 μm wavelength. Chromatic dispersions are flat. The values of dispersion increase with increasing filling factor d/Λ and decrease with the increase in lattice constant Λ. In particular, some chromatic dispersion curves also cut the zero-dispersion line at two points. The flat dispersion feature, high nonlinearity, and small confinement loss of the proposed photonic crystal fiber structure make it suitable for supercontinuum

Optical pulse Self-compressor combined the Nonlinear coupler with Backward Raman fiber amplifier

Based on the nonlinearity of the nonlinear optical coupler (NOC) and the amplifying capacity of the backward Raman fiber amplifier (PBRFA), a new optical system to compress the optical pulse (optical pulse self-compressor: OPSC) is proposed. Using the expressions describing relationship between output intensities from both output ports and input one of NOC and the expression describing the amplification of the PBRFA, the compressing process of the optical pulse propagating through OPSC is simulated. The results show that the peak of optical pulse will be enhanced and the duration of optical pulse will be reduced significantly, and the shape of input pulse is completely compressed with certain efficiency. It means the optical pulse is self-compressed without the pump pulse

INFLUENCE OF STRUCTURAL PARAMETERS ON OPTICAL CHARACTERISTICS OF PHOTONIC CRYSTAL FIBERS WITH CIRCULAR LATTICE

We demonstrate in this study that near-zero, ultra-flattened chromatic dispersion can be achieved over a wide range of wavelengths in photonic crystal fibers (PCFs) by means of slight variations in the geometrical parameters of the cladding. To do that, a new solid-core circular PCF design with various air hole diameters and lattice constants is presented, and the design features are numerically analyzed in detail. After 40 simulations, we determined three structures that possess optimal dispersion with the following lattice constants (Ʌ) and filling factors for the first ring (d1/Ʌ): Ʌ = 0.8 µm, d1/Ʌ = 0.45 for #F1, Ʌ = 0.9 µm, d1/Ʌ = 0.45 for #F2, and Ʌ = 1.0 µm, d1/Ʌ = 0.45 for #F3. High nonlinearity and low attenuation are outstanding features of our model. With these advantages, the proposed fibers are targeted for smooth flat broadband supercontinuum generation for near-infrared applications

NONLINEAR CHARACTERISTICS OF SQUARE SOLID-CORE PHOTONIC CRYSTAL FIBERS WITH VARIOUS LATTICE PARAMETERS IN THE CLADDING

Nonlinear characteristics of fused silica, solid-core photonic crystal fibers (PCFs) with a square array of air holes are studied numerically. We present a novel design that emphasizes the difference in air hole diameters in the photonic cladding. These PCFs have the advantages of flat dispersion, high nonlinearity, and low attenuation. Based on simulation results, three optimal structures, denoted #F1, #F2, and #F3, having anomalous and all-normal dispersions in the near-infrared range are selected to investigate characteristic properties at the pump wavelength. Such PCFs open up many possibilities for nonlinear optical applications, especially supercontinuum generation

Comparison of dispersion characteristics of hollow-core photonic crystal fibers filled with aromatic compounds

In this paper, hollow-core photonic crystal fibers (PCFs) infiltrated with benzene and nitrobenzene are designed and investigated. Their dispersion characteristics are numerically simulated. The results show that using the aromatic-compounds-filled hollow core of PCFs makes dispersion curves flat. In addition, the dispersion curves approach the zero-dispersion line closer than previously published dispersion curves of PCFs with toluene, thus significantly improving the supercontinuum generation to create the ultra-flat spectrum expansion