I would remove that window/frame and take the assembly to a GOOD glass shop. If there are still pieces of glass in the frame or at least available, the shop can tell if it is tempered or laminated safety glass. It is NOT common household glass. It will not be a cheap fix, but in comparison, a lot less then from the original manufacturer or distributor (probably Hehr) who will want to sell you the unneeded frame as well. You will need some special sealing tape from any RV dealer to reinstall the assembly.
Dave W along with my DW, Susan and our poodlepups, Callie & Molly,2011 Ford F250 6.7 CCLB, 5er Hitch Option w/B&W Hitch,,Ride Rite air bags, 2014 Montana High Country 343RL (38')