Technology Transfer Case Studies

LIGO Technology Migration

Photo-Thermal Interferometer

Adaptive Beam Shaping

High Power Modulator

Pound-Drever- Hall Locking

Diode Pumped Laser

Slab Laser

Vacuum Cable Clamp

Interferometric Displacement Sensor

Oxide Bonding Techniques

Fast Chirp Transform

Blind Data Search Method

Distributed Identity Management

Holographic Quantum Geometry

Technology Type:  Materials Engineering

Oxide Bonding Techniques for Jointing Silicon Carbide

** Inventors:  Sheila Rowan, James Hough, Eoin John Eliffe
** Institutions:  Glasgow University and Stanford University
** Patent Application:  US2007/0221326)
** Contact:  Sheila Rowan  
      Sheila.Rowan(at)glasgow.ac.uk, 0141.330.4701
** Supporting Agencies:  NSF and PIPSS
** Technology Source:  LIGO Scientific Collaboration (LSC) members
      outside of LIGO Laboratory
** Patent Thumbnail

Jointing techniques with high mechanical strength and stability are required for use in the fabrication of optical systems used in space-based applications such as telescope assemblies and optical benches. The original technique of hydroxy-catalysis, or "silicate" bonding was invented and patented at Stanford University by Gwo (1) for the purpose of jointing the fused silica pieces forming the star-tracking telescope assembly used in the Gravity Probe B space experiment. LIGO has used a variant of this technique to fabricate the quasi-monolithic fused silica suspensions now being installed for Advanced LIGO and previously used in the GEO 600 gravitational wave detector. This technique was selected for use in ground-based gravitational wave detectors because of its high strength with very thin bonding layers combined with low mechanical loss (2), thus maintaining low thermal noise.

The original technology has been transferred to a number of optical vendors. Development of Oxide-bonding techniques was supported by a PIPSS technology transfer award to SpanOptic Ltd (UK), with a patent granted for bonding silicon carbide (US2007/0221326 A1). In addition, further contracts and partnerships have been established in this area with Gooch and Housego (UK), HighYaG (Germany) and Calyxo (USA).

References

1.  Gwo, D-H2001  Ultra precision and reliable bonding method  United States Patent Number US6284085B1
2.  Mechanical Losses Associated with the Technique of Hydroxide-catalysis Bonding of Fused Silica, S. Rowan et al. Phys. Lett A, 246 (1998) pp471-478.