Photonic chip having a monolithically integrated reflector unit and method of manufacturing a reflector unit

A method of manufacturing a reflector unit on a photonic chip, the method comprising:

• providing a substrate having a top surface with a region of interest, the region of interest being covered with a bulge of a removable material;
• monolithically integrating a layer of reflective material over a portion of the top surface adjacent to the bulge and over a portion of the bulge, the layer of reflective material forming a base monolithically integrated to the portion of the top surface and a pocket monolithically integrated over the portion of the bulge in a manner leaving a portion of the bulge uncovered;
• removing the bulge of the removable material, the pocket having a lateral opening leaving a cavity between the pocket and the region of interest, the cavity receiving an optical axis extending parallel to the top surface, spaced apart from the top surface and through the opening, the layer of reflective material forming a reflector unit for reflecting light at least one of incoming from the region of interest and towards the region of interest;
• and
• recessing a longitudinal trench in the top surface of the substrate and parallel to the optical axis, the longitudinal trench being sized and shaped to receive an end of an external optical waveguide having a propagation axis coinciding with the optical axis.