Optimization of retardance for a complete Stokes polarimeter

We present two figures of merit based on singular value decomposition, whic h can be used to assess the noise immunity of a complete Stokes polarimeter . These are used to optimize a polarimeter featuring a rotatable retarder a nd a fixed polarizer. A retardance of 132 degrees (approximately three-eigh ths wave) and retarder orientation angles of +/-51.7 degrees and +/-15.1 de grees are found to be optimal when four measurements are used. Use of this retardance affords a factor-of-1.5 improvement in signal-to-noise ratio ove r systems employing a quarter-wave plate. A geometric means of visualizing the optimization process is discussed, and the advantages of the use of add itional measurements are investigated. No advantage of using retarder orien tation angles spaced uniformly through 360 degrees is found over repeated m easurements made at the four retarder orientation angles. (C) 2000 Optical Society of America OCIS codes: 120.5410, 120.2130, 260.2130, 260.5430, 100. 3190.