Embodiments herein relate to orthogonally coupling light transmitted from a photonic transmitter chip. An optical apparatus may include a splitter to split light from a light source into a first path and a second path, and a grating to receive light from the first path at a first side and light from the second path at a second side opposite the first side to transmit diffracted light from the first path and the second path in a direction orthogonal to the photonic transmitter chip. Other embodiments may be described and/or claimed.