Fiber optic connections are accomplished with passive alignment using a modular approach. An improved waveguide substrate has precisely aligned waveguides secured in place, including at an inlet channel, an outlet channel, or both. The waveguides need not extend beyond the face of the inlet or outlet location, and there is no need to have any unsupported fiber optic fibers connect to the waveguide substrate. When provided, a connector module or modules have fiber optic fibers having supported ends which precisely align with the waveguides of the waveguide substrate. Connecting pins typically are provided to insure alignment between waveguides and fibers is easily attained.