Organizer tray including a base wall and a receiving wall that is coupled to the base wall. The base and receiving walls extend parallel to each other along a lateral axis. The receiving wall extends away from the base wall along an elevation axis that is perpendicular to the lateral axis such that the base and receiving walls define a circuit channel. The receiving wall has a curved shape. The base and receiving walls are shaped to hold a flex circuit assembly within the circuit channel, in which the flex circuit assembly includes a fiber-routing substrate and corresponding segments of optical fibers that extend within the fiber-routing substrate. The base and receiving walls are configured to hold the fiber-routing substrate such that the fiber-routing substrate satisfies a bend radius of the optical fibers.