Dear Maria,

To pass the long waves and absorb the shorter waves one can use indirect band gap semiconductor materials. For examples silicon has a cut off wavelength of about 1 micrometer where the shorter wavelengths with be absorbed while the longer wavelengths will be passed through the material. The required thickness will be about 300um of single crystalline silicon with low doping concentration since the free carriers absorb the long waves. The absorbed shorter waves will generate electron hole pairs that recombine again mostly nonradiatively. Therefore they will not re emit again. If any emission it will be very weak. 

Best wishes