Side-polished photonic crystal fiber sensor with ultra-high figure of merit based on Bloch-like surface wave resonance

•Bloch surface wave-based sensors have been shown to be superior to surface plasmon resonance-based sensors in numerous studies.•A Bloch-like surface wave resonance configuration is introduced for biosensing with an ultra-high figure of merit using a side-polished PCF.•The air-hole periodic microstructure of the PCF cladding constitutes a two-dimensional PC for generating BLSW resonance conditions.•The proposed configurations are very sensitive with narrower resonances to design sensors with an ultra-high figure of merit.