  Submillimeter (and in some cases millimeter) wavelength continuum
measurements are presented for a sample of 40 active galactic nuclei (probably
all quasars) lensed by foreground galaxies. The object of this study is to use
the lensing boost, anywhere from ~3- 20 times, to detect dust emission from
more typical AGNs than the extremely luminous ones currently accessible without
lensing. The sources are a mix of radio loud and radio quiet quasars, and,
after correction for synchrotron radation (in the few cases where necessary),
23 of the 40 (58%) are detected in dust emission at 850um; 11 are also detected
at 450um. Dust luminosities and masses are derived after correction for lensing
magnification, and luminosities are plotted against redshift from z = 1 to z =
4.4, the redshift range of the sample. The main conclusions are (1)
Monochromatic submillimeter luminosities of quasars are, on average, only a few
times greater than those of local IRAS galaxies; (2) Radio quiet and radio loud
quasars do not differ significantly in their dust lumimosity; (3) Mean dust
luminosities of quasars and radio galaxies over the same redshift range are
comparable; (4) Quasars and radio galaxies alike show evidence for more
luminous and massive dust sources toward higher redshift, consistent with an
early epoch of formation and possibly indicating that the percentage of
obscured AGNs increases with redshift.
