Here's a summary of the origin of the throughput data for NICMOS that
was delivered to CDBS back in February:

Filters (including polarizers): Manufacturer's pre-fabrication specs
                                received from Ball Aerospace, Dec. 1994.

Grisms: No data available at this time; filled with 1's for now.

Detector DQE's: Data received from Rodger Thompson (NICMOS PI; Univ. of Arizona)
                in January 1995 that was measured in the lab for 3 candidate
                flight detectors.

Mirrors and dewar windows: No measured data available at this time.
                           Wavelength-independent values of 0.90 and 0.95
                           used for now, taken from Rodger Thompson's
                           "Scientist's Guide to NICMOS", Table 2.