A single-mode semiconductor diode laser operating in the strong optical feedback regime and tunable within the D-1 line of the Cs atom

The importance of using the D-1 line of the Cs atom in atomic and optical p hysics experiments is clarified. The development of an external-cavity diod e laser system suitable to excite the D-1 line of the Cs atom, which occurs at 895 nm, is presented. The laser is operated in the strong optical feedb ack regime. The effect of the feedback strength on the system performance i s analyzed. Under the condition of strong optical feedback, a single-mode l inewidth of approximate to1.8 MHz, a continuous tuning range of approximate to 20 GHz (at the fixed angle of the grating), and a laser output power of approximate to 10 mW are demonstrated. Using the well-known values of the hyperfine splitting in the Cs atom, we determine the temperature and curren t tuning rates with an external cavity to be approximate to 31.5 GHz/degree sC and approximate to0.9 GHz/mA, respectively. The laser is demonstrated to be tunable to any of the dipole-allowed hyperfine transitions within the D -1 line of the Cs atom. In addition this laser is suitable for incoherent o ptical pumping as required in lasing without population inversion experimen ts. The capability of using this laser in an electromagnetically induced tr ansparency experiment is demonstrated. (C) 2001 Published by Elsevier Scien ce B.V.