Dichroic Mirrors are commonly used in laser technology. Dichroic mirrors/beamsplitters transmit or reflect light according to wavelength to achieve spectral splitting. Long-pass dichroic mirrors highly reflect light below the cut-off wavelength and highly transmit light above the cut-off wavelength. Short-pass dichroic mirrors, in contrast, highly transmit light below the cut-off wavelength and highly reflect light above the cut-off wavelength.