A variation-tolerant receiver includes a plurality of receiver resonators configured to demultiplex a multiplexed modulated signal received from at least one wavelength division multiplexing (WDM) transmitter having a plurality of transmitter resonators and wherein operationally each of the receiver resonators has a receiver resonance linewidth not exceeding a minimum spacing between two adjacent transmitter resonances of the transmitter resonators, the receiver resonances collectively spanning a free spectral range of one of the receiver resonators such that the variation-tolerant receiver achieves gapless spectral response. A method passively compensates transmitter-receiver channel mismatch in a transceiver by: separating a broadband carrier into a plurality of narrowband transmitter carriers; modulating the narrowband transmitter carriers to form a plurality of modulated signals; multiplexing each of the modulated signals to form a multiplexed modulated signal; and demultiplexing the multiplexed modulated signal onto a plurality of receiver channels.