Chris Lowrie

L3Harris Corporation · Photonics and Quantum Sciences

Results of a hydrogen sensor based on light scattering from a porous silicon surface coated with a thin palladium film are discussed. Reflected light scattered from the rough surface of porous silicon surface with a thin palladium film is compared before and after exposure to hydrogen gas. After exposure to hydrogen gas the sensor's optical reflect...

Discrete wavelet image processing techniques are applied to AFM images of Palladium for improving image quality. In this paper Discrete Wavelet Transforms (DWT) are used to process AFM images to minimize the noise introduced by AFM instrumentation errors. The smallest of mechanical and electrical errors from the AFM introduces noise into the images...

In this paper we excite the surface of porous silicon with incoherent, broad band white light and observe the spectrum of colors reflected from the surface. Using an atomic force microscope images from red and green porous silicon samples are collected. In this paper we relate the optical color of the surface to the size of scattering features on t...

Results of a hydrogen sensor based on light scattering from a porous silicon surface coated with a thin palladium film are discussed. Reflected light scattered from the rough surface of porous silicon surface with a thin palladium film is compared before and after exposure to hydrogen gas. After exposure to hydrogen gas the sensor's optical reflect...

In this paper we excite the surface of porous silicon with incoherent, broad band white light and observe the spectrum of colors reflected from the surface. Using an atomic force microscope images from red and green porous silicon samples are collected. In this paper we relate the optical color of the surface to the size of scattering features on t...

A method of infrasonic signal classification using hermite polynomials for signal preprocessing is presented. Infrasound is a low frequency acoustic phenomenon typically in the frequency range 0.01 Hz to 10 Hz. Data collected from infrasound sensors are preprocessed using a hermite orthogonal basis inner product approach. The hermite preprocessed s...

A method of signal classification using Hermite polynomials for signal preprocessing is presented. Low frequency acoustic signals are preprocessed using a Hermite orthogonal basis inner product approach. The Hermite preprocessed signals result in feature vectors that are used as input to a parallel bank of radial basis function neural networks (RBF...

An integral part of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) International Monitoring System is an infrasound-monitoring network. This network has the capability to detect and verify infrasonic signals-of-interest (SOI), e.g., nuclear explosions, from other unwanted infrasound noise sources. This paper presents classification results of inf...

An efficient method of demodulation of a received signal is proposed. A computationally efficient wavelet demodulation receiver is described for use in a handset cell phone. It will be demonstrated that the wavelet demodulation receiver has improved performance over a matched filter. Using this simple method extends the battery lifetime of a cellul...

We present an experimental investigation of the energy statistics of the linear polarization components of pulses from a Nd:YAG laser that is repetitively Q-switched with an acousto-optic modulator. Varying the modulator-induced diffraction losses leads to changes in the pulse polarization state and the energy statistics of the polarization compone...

We describe control of the polarization state of a diode-pumped Nd:YAG laser that is Q switched with an acousto-optic modulator (AOM). One of two orthogonal linear polarization states can be made dominant, depending on the amount of loss introduced by the AOM. Heterodyne beating indicates that the two polarization states are of slightly different f...

This paper presents the designs and experimental results of Northrop peniotron amplifiers at 8 GHz and in the harmonic mode at 16 GHz. All tubes were zero drive stable due to an attenuator inserted into the quadruple ridge waveguide. Waveguide transitions close to cut-off frequencies are described. Also discussed are the design and preliminary test...