We propose an on-chip reflectivity-tunable single wavelength reflector, based on a coupling-modulation microring with an integrated reflective element. Reflectivity ranging from 0 to 1 can be obtained by tuning the coupling coefficient. With the reflective element parameters chosen carefully, the operation bandwidth of the reflector can be designed to accommodate the input signal with different bit rates and modulation formats.
Combining the proposed reflector with delay-tunable photonic elements, an on-chip reconfigurable optical correlator is proposed. This on-chip optical correlator demonstrates reconfigurability, scalability, and size reduction, and thus, it is promising for on-chip optical packet switching networks.