Showing papers by "Todd R. Christenson published in 2001"

LIGA for lobster: First observation of lobster-eye focusing from lithographically produced optics

Abstract: The prospect of making a lobster-eye telescope is drawing closer with recent developments in the manufacture of microchannel-plate optics. This would lead to an x-ray all-sky monitor with vastly improved sensitivity and resolution over existing and other planned instruments. We consider a new approach, using deep etch x-ray lithography, to making a lobster-eye lens that offers certain advantages even over microchannel-plate technology.

Wafer scale micromachine assembly method

Abstract: A method for fusing together, using diffusion bonding, micromachine subassemblies which are separately fabricated is described. A first and second micromachine subassembly are fabricated on a first and second substrate, respectively. The substrates are positioned so that the upper surfaces of the two micromachine subassemblies face each other and are aligned so that the desired assembly results from their fusion. The upper surfaces are then brought into contact, and the assembly is subjected to conditions suited to the desired diffusion bonding.

LIGA fabrication of high-aspect-ratio lobster-eye optics

Abstract: Lobster-eye optics are an exciting advance in the field of x-ray astronomy, specifically as focusing optics for wide field of view telescopes. In its simplest form the optic is a square packed array of square-channels. Typical channel dimensions are width 10 - 30 mm, length 300 - 1000 mm, and wall thickness of ~2 - 5 mm. These dimensions raise the question of whether such devices can be made in the deep x-ray LIGA regime. Following recent success in fabricating a low aspect ratio Lobster-eye structure, we discuss some of the parameters for, and production issues involved in making, a useful high aspect ratio Lobster-eye prototype. We report on our initial attempts to produce high aspect ratio Lobster-eye optics using the LIGA process with a Graphite substrate.

Post-Processed Integrated Microsystems

Abstract: This report represents the completion of a three-year Laboratory-Directed Research and Development (LDRD) program to develop a low cost platform for integrated microsystems that is easily configured to meet a wide variety of specific applications-driven needs. Once developed, this platform, which incorporates many of the elements that are common to numerous microsystems, will enable integrated microsystem users access to this technology without paying the high up-front development costs that are now required. The process starts with the fabrication, or acquisition, of wafers which have sparsely placed device or circuit components fabricated in any foundried technology (Si CMOS or bipolar technologies, high-frequency GaAs technologies, MEMS, etc.). We call these “smart substrates.” Using the diverse processing capabilities of SNL, we then intend to “post-process” high-value components in open areas on the front or back of the wafers and microelectronically integrate the added components with the pre-placed circuitry. Examples of post-processed components include sensors, antennas, SAW devices, passive elements, micro-optics, and surface-mounted hybrids. The combination of preplaced electronics and post-processed components will enable the development of many new types of integrated microsystems. Targeted applications include integrated sensor systems, tags, and electromechanical systems.

A plethora of micro-optical systems

Abstract: There are many applications for micro-optics. Perhaps the most exciting use of micro-optics is in fiber optical communication systems, getting the light signals in and out of the fibers. Other possible uses include data processing, chemical sensing, and spectroscopic applications. In this talk we will describe (mu) ChemLab, the Polychromator, a new spectroscopic gas identification device, a fiberoptic status monitor, and a deep X-ray lithographic technique for fabricating micro-optical systems.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Four-function optical switch with LIGA alignment plates

Abstract: The design and on-going fabrication of an opto-electro- mechanical microsystem that acts as a four-function optical fiber switch will be presented. The four functions of the 2x2 optical switch include 1) Normal mode, where channel A and channel B pass light straight through, 2) Loopback mode, where light originating in channel A is detected in the B leg, 3) Monitor A mode, where a probe pulse is inserted into the channel B and any reflections are detected in the A leg, and 4) Monitor B mode, the compliment of 3) above. High spatial frequency gratings etched in fused silica configure the light beams through free-space substrate-mode propagation. The design for an OTDR-mode transmission grating that normally passes light from an incidence angle of 45 degrees within the silica substrate as well as passes light from a normal incidence straight through the silica will be discussed. A miniature commercial drive motor, positioned with LIGA alignment plates, rotates the optical grating disk into one of the four implemented function positions. The impact of required tolerances and packaging limitations on the optics, LIGA alignment plates, and the complete microsystem will be presented.

LIGA for lobster

Abstract: The prospect of making a lobster-eye telescope is drawing closer with recent developments in the manufacture of microchannel-plate optics. This would lead to an x-ray all-sky monitor with vastly improved sensitivity and resolution over existing and other planned instruments. We consider a new approach, using deep etch x-ray lithography, to making a lobster-eye lens that offers certain advantages even over microchannel-plate technology.