Figure 3: Range of frequency conversion.
From: Frequency and bandwidth conversion of single photons in a room-temperature diamond quantum memory
Measured 
of frequency-shifted photons. Frequency conversion, tuning the read beam over a 30 nm range, is observed. Non-classical statistics, that is, 
, are maintained over a 18 nm range. The estimated 
(solid line) which depends on sinc2(ΔkL/2) agrees well with experimental data suggesting that the range of frequency conversion is determined by phase-matching conditions. Error bars show 1 standard deviation calculated assuming Poissonian noise.
