Synthetic Sapphire Absorbance at 1064 nm Robert Berry 15 August 2002

Motivation Attractive physical properties. LIGO II (Advanced LIGO) demands higher sensitivity. Absorbance characterization needed.

Method - PDS Pump Laser Probe Laser Optical Chopper Detector

Procedure Optical Fiber Telescope Alignment Detection

Optical Fiber Noise Reduction Maximizing Power Output Optical Fiber Telescope Alignment Detection Optical Fiber Noise Reduction Maximizing Power Output

Telescope Small Laser Waist 4 X Optical Fiber Telescope Alignment Detection Telescope Small Laser Waist 4 X

Alignment Probe waist: 42.2 mm Beams nearly intersecting Optical Fiber Telescope Alignment Detection Alignment Probe waist: 42.2 mm Pump waist: 32.4 mm Beams nearly intersecting

Detection QUAD Cell Signal Analyzer Optical Fiber Telescope Alignment

Results False-Positive 2-D Mapping Linear Mapping

False-Positive: X

False-Positive: Y

40:1 SNR

2D Mapping (grid is 40 mm square)

Linear Mapping

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