Frequency Standards for Precision Spectroscopy
The well-known spectrum of Rubidium near 780 nm renders it an excellent candidate as a frequency reference. Scott Bergeson of Brigham Young University and his colleagues measured the Yb I
1 transition to an accuracy of better than 0.5 ppb, at 399 nm, in part by transferring the accurately known frequency of the F=2 to F'=(2,3) D2 line of
87Rb to a doubled Ti:sapphire laser via a frequency comb.
The D2-100 Distributed Bragg Reflector Laser is easily locked to the Doppler-free hyperfine spectrum of Rubidium by using the D2-210 Saturated Absorption Spectroscopy Module and D2-125 Reconfigurable Servo. This complete sub-system acts as a stable frequency reference.