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We have imaged 45 quasars from the Sloan Digital Sky Survey (SDSS) withredshifts 1.85 < z < 4.26 in JHKs with the KPNO SQIID imager. By combiningthese data with optical magnitudes from the SDSS we have computed the restframeoptical spectral indices of this sample and investigate their relation toquasar redshift. We find a mean spectral index of <alpha_o> = -0.55+/-0.42 witha large spread in values. We also find possible evolution of the form alpha_o =(0.148+/-0.068)z - (0.964+/-0.200)$ in the luminosity range -28.0 < M_i <-26.5. Such evolution suggests changes in the accretion process in quasars withtime and is shown to have an effect on computed quasar luminosity functions.

Infrared Imaging of SDSS Quasars: Implications for the Quasar K correction