We combine our compilation of photometry of M31 globular clusters and probable cluster candidates with new near-infrared photometry for 30 objects .
Using these data we determine the globular cluster luminosity function ( GCLF ) in multiple filters for the M31 halo clusters .
We find a GCLF peak and dispersion V _ { 0 } ^ { 0 } = 16.84 \pm 0.11 , { \sigma } _ { t } = 0.93 \pm 0.13 ( Gaussian { \sigma } = 1.20 \pm 0.14 ) , consistent with previous results .
The halo GCLF peak colors ( e.g . B _ { 0 } ^ { 0 } - V _ { 0 } ^ { 0 } ) are consistent with the average cluster colors .
We also measure V -band GCLF parameters for several other subsamples of the M31 globular cluster population .
The inner third of the clusters have a GCLF peak significantly brighter than that of the outer clusters ( \Delta V ^ { 0 } \approx 0.5 mag ) .
Dividing the sample by both galactocentric distance and metallicity , we find that the GCLF also varies with metallicity , as the metal-poor clusters are on average 0.36 mag fainter than the metal-rich clusters .
Our modeling of the catalog selection effects suggests that they are not the cause of the measured GCLF differences , but a more-complete , less-contaminated M31 cluster catalog is required for confirmation .
Our results imply that dynamical destruction is not the only factor causing variation in the M31 GCLF : metallicity , age , and cluster initial mass function may also be important .