The LPM Series of long phase masks are available in lengths up to 100 mm for production of and research on fiber Bragg gratings. The phase masks are made by interfering two laser beams, which allows continuous chirp over the entire length of the mask rather than the quantized chirp characteristic of e-beam-written phase masks. The period of each mask can be measured to a precision of 1 nm.
Lasiris, St.-Laurent, Que., Canada