18x36x1.5 inch sapphire panels for visible and infrared windows
Abstract
158 kg sapphire single crystals were grown by horizontal directional solidification method. Bubble-free panels with usable rectangular dimensions of 457 mm x 914 mm x 38 mm (18 x 36 x 1.5 inches) can be cut from the crystals. These are the largest-area sapphire panels ever produced by any technique. Bubble-free sections of the crystal 300 mm x 457 mm and up to 60 mm thick (12 x 18 x 2.36 inches) can also be produced. Growths were performed with graphite heating elements under a controlled atmosphere with automated power control. Results of transmission measurements performed on 5 mm thick samples are presented and the transmission is similar to sapphire grown by other techniques.
- Publication:
-
Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series
- Pub Date:
- May 2017
- DOI:
- 10.1117/12.2269465
- Bibcode:
- 2017SPIE10179E..0NM