Practical method for determining the emission frequency of a distributed feedback diode laser at the D1 line of 133Cs

A practical method to determine the emission frequency of a distributed feedback diode laser at the D1 line of 133Cs is reported. By fitting the extracted dips of the saturated absorption spectrum using linear or quadratic function, this method can realize the measurement of the emission frequency with low cost and simple structure. The test results show that this method can achieve an appreciable measurement range and a high measuring precision of approximately 10 MHz.