A new planar light concentrator design is proposed by using unique diffraction properties of high-contrast
subwavelength gratings (HCGs). HCGs have the ability to diffract the incoming light at steep angles with very high
efficiency. By integrating the HCGs on top of planar glass substrates, light can be guided in the glass leading to high
concentration at the edges. Finite difference time domain simulation results show that concentration ratio close to 50 can
be achieved by optimizing the grating parameters. These planar light concentrators find application in various areas
including concentrated solar power, light pipes and spectrum splitters.