Stable retarder is newest SRM for optics industry

STABLE RETARDER IS NEWEST SRM FOR OPTICS INDUSTRY

Optical retarders, known as waveplates, are critical components for polarization control in the optics industry. They play an important role in optical sensor, data storage, medical and military systems as well as a variety of test and measurement instruments. Waveplate manufacturers typically measure retardance using laboratory benchtop systems with varying uncertainty. Customers also require different levels of retarder uncertainty-ranging from greater than 10 % for multipleorder waveplates to less than 0.1 % for critical devices.

At the urging of several manufacturers, scientists at NIST developed and demonstrated a stable linear retarder for use as a calibration reference. The device is a nominally quarter-wave retarder at 1.3 wm; this wavelength was chosen to meet fiber optic telecommunication needs. The retarder's phase shift is stable within 0.1 over a wavelength range greater than 50 nm, an input angle range greater than 10, and a variation in room temperature greater than 10 oC.

The devices are packaged in a protective housing that ensures retardance stability in the presence of humidity and contamination. NIST estimates the retardance will remain stable within 0.01 for 10 years when the device is stored properly in typical laboratory conditions. Each device will be individually measured and a certified retardance value with an expanded uncertainty less than 0.08deg reported.

The retarder is offered for $5342 as Standard Reference Material 2525. It is available from the Standard Reference Materials Program, Building 202, Room 204, NIST, Gaithersburg, MD 20899-00001, (301) 9756776, <[email protected]>.