An integrated photonic circuit includes waveguides (12-19) and other photonic components. The photonic circuit has a first part (1) and a second part (2), the first part and the second part being connected to a mirror in the form of a half 2×2 multimode interferometer (MMI) (32), which comprises solely one half MMI (31) in a longitudinal direction, the half MMI (32) having two ports (33, 34) and being arranged to reflect half of the light that is incident on one of the ports to one port and transmit half of the incident light to the second port, and the free surface (35) of the half MMI (32) having been treated with a highly reflective material.