Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, June 2005. / Thesis Advisor(s): Phillip E. Pace. Includes bibliographical references (p. 55). Also available online.

Thesis (M.S.)--Oregon State University, 2006. / Printout. Includes bibliographical references (leaves 47-48). Also available on the World Wide Web.

Thesis (Ph. D.)--University of Washington, 2005. / Vita. Includes bibliographical references (leaves 94-98).

Thesis (Ph. D.)--University of Texas at Austin, 2005. / Vita. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2005. / Vita. Includes bibliographical references.

Thesis (M.E.)--University of Canterbury, 2006. / Typescript (photocopy). "November 2006." Includes bibliographical references (leaves 121-124). Also available via the World Wide Web.

Determination of quantitative expression levels of alternatively spliced isoforms provides an important approach to the understanding of the functional significance of each isoform. Real-time PCR using exon junction overlapping primers has been shown to allow specific detection of each isoform. However, this design often suffers from severe cross amplification of sequences with high homology at the exon junctions. We used human GFRα2b as a model to evaluate the specificity of primers substituted with locked nucleic acids (LNAs). We demonstrate here that single LNA substitutions at different positions of 3’ terminus could improve the discrimination of the primers against GFRα2a template, a highly homologous isoform. While LNA substitutions of GFRα2b primer at the residues possessing different sequences as GFRα2a has limited improvement in specificity, two consecutive LNA substitutions preceding the different sequences has dramatically improved the discrimination by greater than 100,000-fold compared to the non-substituted primer. Thus, LNA when substituted at certain residues can allow the discrimination of highly homologous sequences. / Singapore-MIT Alliance (SMA)

Mode-locked fiber lasers have attracted significant scientific and commercial interest since they offer a compact and highly stable platform with straightforward operation for exploiting ultrafast and nonlinear phenomena. They have enabled a vast range of applications that span from distinct disciplines such as medical diagnostics, molecular spectroscopy, and high-power precise mechanical cutting, to optical metrology. Various gain media have been utilized to achieve laser emission at different wavelengths. We have developed unique thulium/holmium (Tm/Ho) doped mode-locked fiber laser systems to address the needs of low-noise ultrafast optical sources in the wavelength vicinity of 2 μm at higher repetition rates. Since the 2 μm wavelength regime has recently attracted more attention with the emergence of thulium gain fibers, the rich underlying cavity dynamics, novel pulse operation regimes and nonlinear phenomena in compact fiber configurations have not been fully explored yet. In this thesis, research is conducted on novel Tm fiber laser cavity configurations and on the formation of unique, polarization-based pulsing regimes. Particularly, this research is focused on the exploration of novel ultrafast and nonlinear phenomena, and the development of optical sources emitting unprecedented ultrafast pulse trains beyond conventional equal-intensity distribution using Tm/Ho doped gain media. The research presented features four main results: 1) development of a high repetition rate and low-noise Tm/Ho doped mode-locked fiber laser platform as an attractive optical source for a wide variety of applications 2) investigation of a novel mode-locked state in which the ultrafast pulse train is composed of co-generated, consecutive, equal intensity and orthogonally polarized pulses in order to achieve dual RF comb generation for dual-comb spectroscopy applications, 3) exploration of controllable ultrafast waveform generation utilizing vector soliton and harmonic mode-locking mechanisms for optical telecommunication applications, and 4) demonstration of unique transitional mode-locked states showing exceptional features such as powerful irregular bursts of ultrafast pulses and rogue wave behavior without damaging the laser elements. The aim of these projects has been to explore the novel optical properties of Tm/Ho co-doped fiber lasers in order to achieve advanced functionalities in commonly practiced applications such as telecommunication, metrology and spectroscopic applications. / 2019-10-22T00:00:00Z

As memory I/O bandwidth continues to increase beyond the current multi-gigabit rates for high performance computer systems, there remains a need for a stable and robust method of clock synchronization capable of transferring data reliability between main memory and a CPU memory controller. A Delay Locked Loop (DLL) is often utilized in such a system where synchronization and removal of clock skew are necessary. Synchronization in DLL’s is carried out by continually adjusting the phase of a clock signal by adding or removing delay based on feedback provided by a Phase Detector (PD). Once phase alignment occurs, the DLL is said to be in a “Locked” state. Delay can be produced with either a VCDL (Voltage Controlled Delay Line), or a DCDL (Digitally Controlled Delay Line). Each type of delay line has their own benefits and drawbacks, many of which will be discussed throughout this paper. This thesis provides an overview of previous DLL design research, and presents a functional 45nm CMOS, 200-833 MHz delay locked loop.

This master thesis presents an experimental design of a laser gyroscope based on a stabilized fiber optical parametric oscillator frequency comb and the results of testing of the proposed design. Before going into the experimental details, a background for different types of gyroscopes is discussed. This new laser gyroscope design is made up of only polarization maintaining (PM) fiber and PM fiber components. By using only fiber and fiber components, we were able to minimize size, weight, and alignment issues that are typical in bulk optical designs for OPO's and gyroscopes. The fiber-based OPO produces counter propagating ultrafast pulses that overlap only twice in the cavity, resulting in a beatnote signal when combined outside of the laser cavity. A mode-locked laser is used as a pump source so the lock-in effect (or deadband region) is avoided for the experiment. The drift of this beatnote signal represents the rotation sensitivity of the experimental setup. Issues seen in past iterations, such as stability of mode-locked pump source and beatnote drift overtime due to environmental variables, have been reduced in this experiment. This has been done by comprising the entire pump source of PM components, and by placing the entire setup in an insulating box to minimize acoustic and temperature fluctuations. By creating a frequency comb and locking the laser gyroscope to an optical clock, this experiment can be used for very precise rotation sensing in comparison to other gyro designs currently available.