Wireless Ad-Hoc Mesh Networks are characterized by static nodes connected in a mesh topology. A routing protocol discovers and maintains the route for successful transmission of data in a network. The routing protocol should also provide load balancing and fault tolerance for improved network performance. In Free Space Optical networks (FSO) line of sight (LOS) should be maintained between the two communicating nodes. In a multihop scenario maintaining LOS during routing is a challenge. In this paper we propose a routing protocol Quality of Service-Directional Routing Protocol (QDRP) - which assures a certain level of performance to a data flow in terms of delay and implemented on FSO MANET. Through simulations it is observed that QDRP chooses the path with the least delay and performs satisfactorily under varying node densities and transmission rates achieving end to end delay of .14 s and packet delivery percentage of 96% when simulated for an area of 1300 m *1300 m for 100 nodes. This work explores the potential of the proposed routing protocol for free space optical mesh networks. QDRP is compared with ORRP (Orthogonal Rendezvous Routing Protocol) and AODV (Ad-Hoc on Demand Distance Vector), a reactive protocol which is also implemented in free space optical environment. We support our conclusions that QDRP gains in terms of packet delivery percentage, end to end delay and goodput.