Flat Millimeter-Wave Noise Generation by Optically Mixing Multiple Wavelength-Sliced ASE Lights

We propose a photonic method for flat spectrum millimeter-wave (mm-wave) noise generation. Specifically, the flat spectrum mm-wave noise is obtained by slicing the broadband ASE optical spectrum into multiple Gaussian-shaped spectra with different central wavelengths, then beating in a wideband photomixer. Our simulation demonstrates that flat spectrum mm-wave noise can be generated in a very large range of frequency of F-band (90-140 GHz) and G-band (140-220 GHz). For the quantitative comparison of the quality of generated mm-wave noise, we define the relative flatness ( $\eta$ ) as the ratio of the generated noise power fluctuation to its average power within a certain frequency range. Our experimental results show that the relative flatness of the generated mm-wave noise is as low as 0.46 (@35 ± 15 GHz).