Design of multi-order diffractive THz lenses

Quadratic, multi-order diffractive lenses have been designed, fabricated, and demonstrated for the MMW-THz region, with the capability of focusing harmonic wavelengths on to a common focal point. Design wavelength and harmonic spacing can be chosen as design parameters, allowing great flexibility in lens design. Simulations were carried out to determine lens parameters and performance. These lenses reduce both spherical and chromatic aberrations at harmonic wavelengths, and are thinner and lighter than traditional refractive elements. This lens type is potentially useful to sensor fusion architectures.