Knowledge Bank

The sub-Doppler saturation spectrum of the $\mathrm{<mrow\; data-mjx-texclass="ORD">14</mrow>}$N$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$$\mathrm{<mrow\; data-mjx-texclass="ORD">16</mrow>}$O near 4.5 $\mu$m is studied using a mW-level DFG (Difference Frequency Generation) source. The DFG radiation is generated by a Ti:sapphire laser and a Nd:YAG laser amplified by a 10-W fiber amplifier in a 45-mm long PPLN (Periodically-Poled Lithium Niobate) crystal. The Nd:YAG laser is frequency-doubled and frequency stabilized on one $\mathrm{<mrow\; data-mjx-texclass="ORD">127</mrow>}$I$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$ hyperfine transition. The Ti:sapphire laser is locked onto the center of N$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$O transition and its frequency is measured by an OFC (Optical Frequency Comb). In this talk, we will report our measurements of the fundamental band of N$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$O near 4.5 $\mu$m. \