Air spaced zero order waveplate is composed of two quartz crystals, which are installed inside a bracket to form an air gap and have orthogonal optical axes. This design enables zero order phase delay to be generated by the thickness difference between two quartz pieces. By adjusting the thickness difference between the two materials, zero order phase delay can be achieved The Air spaced zero order waveplate has a large wavelength bandwidth and temperature bandwidth, and all surfaces are coated with anti reflective films, which have been installed on brackets for easy integration into optical systems.