From: "James L Blue" Message-Id: <9712191224.ZM19186@azure.cam.nist.gov> Date: Fri, 19 Dec 1997 12:24:12 -0500 X-Mailer: Z-Mail (3.2.3 08feb96 MediaMail) To: blue@nist.gov, paek@nist.gov, cwatson@nist.gov, pgrother@nist.gov, cwilson@nist.gov Subject: OPD for collimating lens New jpeg OPD maps are on magi, in ~blue/optic. They are also available, as is this letter, on fpt://math.nist.gov/pub/blue/. They are deviations from the mean OPD over the map. The olor code is my old standard: black is 0; red is +, yellow ++, light yellow +++; blue is -, cyan --, light cyan ---. These are calculations, for Zernike polynomials through 8th order, which gives slightly (but noticeably) different maps from 6th order. The one at 751 (75.1 mm source from lens surface) is about at the focus. The other two are 0.1mm on either side. The scales for the maps are different on each plot, equal to the Maxd (maximum deviation) column. The third column is the rms OPD. Maxd and Rms are in units of wavelength. Maxd Rms 752 2.016 0.788 751 0.470 0.294 750 1.701 1.213 A curve of the OPD along a radius for 751 (near focal length) is reasonably close to a minimax fit: the extrema are -.33, +.46, -.47, +.09. I suppose this would be called an 0.3 lambda lens? -- Jim Blue ... Gaithersburg, MD blue@nist.gov