Archeota, Spring 2016

https://scholarworks.sjsu.edu/saasc_archeota/1002/thumbnail.jp

Archeota, Fall 2015

https://scholarworks.sjsu.edu/saasc_archeota/1001/thumbnail.jp

Designing of equipments for machining of high pressure pump housing.

Cílem této práce byla konstrukce nového přípravku na obrábění těles nových typů vstřikovacích čerpadel CP3. Na základě kritérií z hlediska ergonomie, obrábění, tvaru tělesa a nákladů byl zkonstruován přípravek, který umožní upnutí a obrobení požadovaných obráběných ploch na tělese. Konstrukce byla provedena v 3D CAD systému, ze kterého je k dispozici výkresová dokumentace i 3D data.The goal of this work was engeneering of new equipment for cutting operation in focus on new type of High Pressure Pumps CP3. Based on criteria from point of view of ergonomics, machining, shape of the housing and costs, equipment has been engeneered which allows to clamp and finish cutting of the required surface on the housing. Equipment designing has been perfomed in 3D CAD software which is able to provide with drawings and 3D data.

Wide-bandwidth mode-hop-free tuning of extended-cavity GaN diode lasers

We present a new approach for extended-cavity diode-laser tuning to achieve wide mode-hop-free tuning ranges. By using a multiple piezoactuated grating mount, the cavity length and grating angle in the laser can be adjusted independently, allowing mode-hop-free tuning without the need for a mechanically optimized pivot-point mount. Furthermore, synchronized diode injection-current tuning allows diode lasers without antireflection coatings to be employed. In combination these two techniques make the construction of a cheap, efficient, and easily optimized extended-cavity diode laser possible. A theoretical analysis is presented for optimal control of piezoactuator displacements and injection current to achieve the widest possible mode-hop-free tuning ranges, and a comparison is made with measurements. The scheme is demonstrated for blue and violet GaN lasers operating at similar to 450 nm and similar to 410 nm, for which continuous tuning ranges exceeding 90 GHz have been achieved. Examples of applications of these lasers are also given

Frequency shifting of pulsed narrow-band laser light in a multipass Raman cell

A multipass cell is described which allows efficient stimulated Raman frequency shifting for low pump laser intensities and low gas pressures. The latter is important for Raman shifting of narrow-band Fourier-transform limited light pulses (Δv=75 MHz). It is shown that frequency broadening of the Raman shifted light can be largely avoided in the Dicke narrowing regime at low pressures. For 75 MHz pump pulses and an H2 density of 2.5 amagat we found a negligible broadening to 90 MHz of the stimulated Stokes light. This is far below the value of 250 MHz expected from spontaneous emission. The narrow-band Stokes pulses achieved in CO2 enabled us to measure the pressure shift coefficient (-0.71×10-2 cm-1/amagat) of this gas. It is demonstrated, for the example of benzene, that our technique provides a very practical light source for high resolution molecular spectroscopy

A prism reflector of anti-resonant ring configuration

Two identical prisms are combined to form an anti-resonant ring reflector, giving total reflection without the use of coatings or roof edges. When used as the total reflector in a Q-switched Nd:YAG laser this device has shown a damage threshold twice that of a multilayer reflector