An Optical Network on Chip (ONoC) relies on a switch that is capable of routing information from one element of the chip to another one, presenting both high data rate and reduced latency during transmission. One efficient way to achieve such functionality, is to combine elementary 4x4 switches to form a general YxY switch. We propose here to enhance this elementary block into a reconfigurable non-blocking 4x4 switch that can take advantage of Wavelength Division Multiplexing to improve its global data rate. For added flexibility, we ensure wavelength granularity so that each connection adapts the number of wavelength taken to its needs. On the one hand, in a single wavelength configuration, we achieve the first fully non-blocking 4x4 switch with double-rings that is compared to state of the art achievements. On the other hand, in a n-wavelengths WDM configuration, we demonstrate the behavior of our reconfigurable nonblocking granular WDM switch with double or single rings. Each ring (or double ring) is thermally tuned during a setup step, to place the resonant peak exactly where expected, to ensure stability of the switch. This architecture is scalable at will, and can be used in a YxY n-wavelengths switch for reconfigurable architectures, that could then benefit from WDM’s increased data rate for applications in High Performance Computing.