Chen, Yi-Ting Ph.D., Purdue University, May 2015. Laser Scanner Jitter Characterization, Page Content Analysis for Optimal Rendering, and Understanding Image Graininess. Major Professor: Jan P. Allebach. In Chapter 1, the electrophotographic (EP) process is widely used in imaging systems such as laser printers and office copiers. In the EP process, laser scanner jitter is a common artifact that...

Fluorescence lifetime imaging (FLi) could potentially improve exogenous near-infrared (NIR) fluorescence imaging, because it offers the capability of discriminating a signal of interest from background, provides real-time monitoring of a chemical environment, and permits the use of several different fluorescent dyes having the same emission wavelength. We present a high-power, LED-based, NIR li...

PURPOSE To record the distribution and spectrum of human retinal pigment epithelial cell lipofuscin (LF) by two-photon-excited fluorescence (TPEF) and confocal laser scanning microscopy. METHODS Ex vivo TPEF imaging of the human retinal pigment epithelium (RPE) of human donor eyes was conducted with a multiphoton laser scanning microscope that employs a femtosecond Ti:sapphire laser as an exc...

Night vision and related thermal imaging systems play a critical role in the protection of our nation's security. These systems record images using video cameras designed for operation in the infrared (IR) region of the light spectrum. As with any imaging system, increased functionality and new information is gained when discrete portions of the observed light spectrum are analyzed separately u...

IMPORTANCE Laser ablation is a rapid and minimally invasive approach for the treatment of superficial skin cancers, but efficacy and reliability vary owing to lack of histologic margin control. High-resolution reflectance confocal microscopy (RCM) may offer a means for examining margins directly on the patient. OBSERVATIONS We report successful elimination of superficial and early nodular bas...

The spatial coherence of laser sources has limited their application to parallel imaging and projection due to coherent artifacts, such as speckle. In contrast, traditional incoherent light sources, such as thermal sources or light emitting diodes (LEDs), provide relatively low power per independent spatial mode. Here, we present a chip-scale, electrically pumped semiconductor laser based on a ...

Many imaging applications require increasingly bright illumination sources, motivating the replacement of conventional thermal light sources with bright light-emitting diodes, superluminescent diodes and lasers. Despite their brightness, lasers and superluminescent diodes are poorly suited for fullfield imaging applications because their high spatial coherence leads to coherent artefacts such a...

Many technological advancements of the past decade have contributed to improvements in the photon efficiency of the confocal laser scanning microscope (CLSM). The resolution of images from the new generation of CLSMs is approaching that achieved by the microscope itself because of continued development in digital imaging methods, laser technology and the availability of brighter and more photos...

We present the implementation of intensity-modulated laser diodes for applications in frequency-domain pump-probe fluorescence microscopy. Our technique, which is based on the stimulated-emission approach, uses two sinusoidally modulated laser diodes. One laser (635 nm) excites the chromophores under study, and the other laser (680 nm) is responsible for inducing stimulated emission from excite...