Ultra-Precise Frequency Conversion Using an Electro-Optic-Modulation Frequency Comb

We demonstrated that an electro-optic-modulation (EOM) comb can work as a noise booster and a highsensitivity detector for detecting the magnified noise from microwave and millimeter-wave signal generators (SGs). Our method can generate low-noise and continuously frequency-variable microwave and millimeter-wave signals. In addition, we can overcome the disadvantage of the EOM comb. The noise in 25-GHz signals can be reduced to ‒110dBc/Hz at a 1-kHz offset frequency from the center frequency. The noise with our method is one-hundred times lower than the lowest noise reported for commercially available SGs. Even lower noise will be achieved if we use a reference laser that is further away from the center frequency of the seed laser. In addition, the output frequency of microwave and millimeter-wave signal generators can be expanded for their universal use. We succeeded in generating low-noise signals at continuously variable frequencies over the range from 6 to 72 GHz.