Rainbow Optics offers many products including waveplates . They offer Multiple-Order Quartz Waveplates, Zero-Order Quartz Waveplates, Optical Beam Isolators and more! Rainbow Optics offers a graph and specifications and more information for each waveplate. To view these graphs or for more information about Rainbow Optics waveplates and their other optic services visitwww.rainbowoptics.com.