We demonstrate electrical tunability of a fiber laser using a liquid crystal photonic bandgap fiber. Tuning of the laser is achieved by combining the wavelength filtering effect of a tunable liquid crystal photonic bandgap fiber device with an ytterbium-doped photonic crystal fiber. We fabricate an all-spliced laser cavity based on the liquid crystal photonic bandgap fiber mounted on a silicon ...

Bandgap Reference voltage chip is implemented in 0.25μm CMOS technology with ESD protection. This chip can be designed by using a layout tool micro wind 3.1.7 version. The chip circuit generates a reference voltage of 1.23 V. It can operate between 20oC & 70oC temperature. Band gap core produces a voltage that is insensitive to variation in temperature. It has a unique protection with respect t...

We have performed time-resolved spectroscopy on InAs quantum dot ensembles in photonic crystal membranes. The influence of the photonic crystal is investigated by varying the lattice constant systematically. We observe a strong slow down of the quantum dots’ spontaneous emission rates as the two-dimensional bandgap is tuned through their emission frequencies. The measured band edges are in full...

We have fabricated diamond-like silicon photonic crystals through a sequential silica/silicon chemical vapor deposition (CVD) process from the corresponding polymer templates photopatterned by holographic lithography. Core-shell morphology is revealed due to the partial backfilling of the interstitial pores. To model the shell formation and investigate its effect to the bandgap properties, we d...

A bandgap reference circuit that uses high-voltage drainextended MOS (DeMOS) devices is presented for high supply voltage application without using a voltage regulator for the bandgap core circuit. The bandgap reference circuit was fabricated using commercially available 0.18μm high-voltage DeMOS technology. Measurement result of the chip shows that the reference voltage change rate for VDD var...

We present detailed theoretical and numerical analysis of certain novel non-linear optical phenomena enabled by photonic bandgap fibers. In particular, we demonstrate the feasibility of optical bistability in an axially modulated nonlinear photonic bandgap fiber through analytical theory and detailed numerical experiments. At 1.55microm carrier wavelength, the in-fiber devices we propose can op...

Photonic-bandgap materials, with periodicity in one, two or three dimensions, offer control of spontaneous emission and photon localization. Low-threshold lasing has been demonstrated in two-dimensional photonic-bandgap materials, both with distributed feedback and defect modes. Liquid crystals with chiral constituents exhibit mesophases with modulated ground states. Helical cholesterics are on...

Cadmium telluride (CdTe) has been recognized as a promising photovoltaic material for thin-film solar cells because of its near optimum bandgap of ~1.5 eV and high absorption coefficient. The energy gap is near optimum for a single junction solar cell and the high absorption coefficient allows films as thin as 2 μm to absorb more than 98% of the above-bandgap radiation. Cells with efficiencies ...

Optimized topology of bi-material acoustic metamaterial lattice plates is studied for maximized locally resonant bandgap of flexural guided waves. Optimized layout of the two relatively stiff and compliant material phases in the design domain is explored, free from any restrictions on the topology and shape of the relevant domains. Multiobjective optimization is performed through which maximize...

the aluminum oxide materials are widely used in ceramics, refractories and abrasives due to their hardness, chemical inertness, high melting point, non-volatility and resistance to oxidation and corrosion. the paper describes work done on synthesis of α-alumina by using the simple, non-expensive solution combustion method using glycine as fuel.aluminum oxide (al2o3) nanoparticles were synthesiz...