In this paper we investigate the application of CDMA in optical communication networks. Optical fiber based communication systems has advantage of having access to large bandwidth and ultra–high speed signal processing are possible. Optical code division multiple access (O-CDMA) is evolving into a promising candidate for access networks, due to its potential for enhanced information security, s...

Abstract: An optical header replacement technology based on Self Electro-optic Effect Devices (SEEDs) is presented. By using the measurement result of a 75 μm long SEED device, we simulate an 8 Gbps throughput is achievable. Based on the switching characteristics of SEEDs, we proposed several methods to improve the SEEDs switching speed. An ultra fast switching speed at 50 Gbps is achievable by...

We describe direct measurements at a high temporal resolution of the changes experienced by the phase and amplitude of an ultra-short pulse upon propagation through an inhomogenously broadened semiconductor nanostructured optical gain medium. Using a cross frequency-resolved optical gating technique, we analyze 150 fs-wide pulses propagating along an InP based quantum dash optical amplifier in ...

Abstract Light’s orbital angular momentum (OAM) with inherent mode orthogonality has been suggested as a new way to the optical encryption. However, dependence of annular intensity profiles on topological charge complicates nanoscale light–matter interactions and hampers ultra-secure encryption application. In this paper, we demonstrate image by tightly focusing perfect vortex (POV) beams contr...

In this work, we report low-loss single-mode integrated optical waveguides in the near ultra-violet and visible spectral regions with aluminum oxide (Al(2)O(3)) films using an atomic layer deposition (ALD) process. Alumina films were deposited on glass and fused silica substrates by the ALD process at substrate/chamber temperatures of 200 °C and 300 °C. Transmission spectra and waveguide measur...

The generation of high-repetition-rate optical frequency combs with an ultra-broad, coherent and smooth spectrum is important for many applications in optical communications, radio-frequency photonics and optical arbitrary waveform generation. Usually, nonlinear broadening techniques of comb-based sources do not provide the required flatness over the whole available bandwidth. Here we present a...

High repetition rate (10-50GHz) semiconductor mode-locked lasers (MLL) provide excellent performance in terms of stable output and high optical power and they are commonly investigated for optical frequency comb generation and optical code division multiple access (O-CDMA) networks [1, 2]. However, there have been few studies of monolithically integrated low frequency (< 2-GHz) semiconductor ML...

Accurate optical methods are required to determine the energy bandgap of amorphous semiconductors and elucidate the role of quantum confinement in nanometer-scale, ultra-thin absorbing layers. Here, we provide a critical comparison between well-established methods that are generally employed to determine the optical bandgap of thin-film amorphous semiconductors, starting from normal-incidence r...