We consider the design of synthetic embedded feedback circuits that can implement desired changes in the concentration of the output of a biomolecular process (reference tracking in control terminology). Such systems require the use of a “subtractor”, to generate an error signal that captures the difference between the current and desired value of the process output. Unfortunately, standard imp...

Judicious chirping of a directly modulated pump laser is used to broaden the intrinsic linewidth of stimulated Brillouin scattering in an optical fiber. The modulation waveform is designed to obtain a spectrum with sharp edges, resulting in phase gradients stronger that those obtained for random pump modulation. The gain and phase frequency response of the slow light process are measured by a v...

We report on a theoretical analysis for the narrowband multiple wavelengths filter in aperiodic optical superlattice (AOS). The sequences of the opposite domains in AOS are optimized to realize the prescribed multiple wavelengths filtering using simulated annealing (SA) algorithm. Two, three and four wavelengths narrowband filters at telecommunication wavelength (near 1550 nm) are presented. Th...

We generate ultrabroadband biphotons via the process of spontaneous parametric down-conversion in a quasi-phase-matched nonlinear grating that has a linearly chirped poling period. Using these biphotons in conjunction with superconducting single-photon detectors (SSPDs), we measure the narrowest Hong-Ou-Mandel dip to date in a two-photon interferometer, having a full width at half maximum (FWHM...

An optical coherence microscope (OCM) has been designed and constructed to acquire 3-dimensional images of highly scattering biological tissue. Volume-rendering software is used to enhance 3-D visualization of the data sets. Lateral resolution of the OCM is 5 mm (FWHM), and the depth resolution is 10 mm (FWHM) in tissue. The design trade-offs for a 3-D OCM are discussed, and the fundamental pho...

We have demonstrated picosecond optical parametric generation in reverse proton-exchanged waveguides in periodically poled lithium niobate with thresholds as low as 200 pJ. Near-transform-limited near-infrared pulses were obtained from cascaded optical parametric generation. For a 1.8-ps (FWHM) pump pulse at 769.6 nm, a saturated internal photon-conversion efficiency of 33% was obtained with 1 ...

Quantum-dot cellular automaton (QCA) is an up-coming nanotechnology in the area of nanoelectronics and is found to be an alternative solution to replace conventional CMOS technology for several reasons. It has attractive features such as faster speed, smaller size, and low power consumption compared to transistor-based technology. The experiments carried out in QCA demonstrated and realized the...

In this paper, we present a new non-restoring square root algorithm that is very efficient to implement. The new algorithm presented here has the following features unlike other square root algorithms. First, the focus of the “nonrestoring” is on the “partial remainder”, not on “each bit of the square root”, with each iteration. Second, it only requires one traditional adder/subtractor in each ...