Stabilization of the emission frequency of 1.54 mu m DFB laser diodes to hydrogen iodide

Comparison of Three Optical Frequency References for HDWDM Systems under Field Conditions

“…This value is in good agreement with the value of 1/100 found by Bertinetto et al [11] for stabilizing a DFB laser diode to a hydrogen iodide absorbtion line at 1540 nm.…”

Phase noise reduction by self-phase locking in semiconductor lasers using phase conjugate feedback

“…Direct phase noise reduction has been obtained by conventional external optical feedback from long external cavities [I], by locking to atomic lines [2], and by locking to interferometers [3]. Indirect phase noise reduction has been obtained in dual laser signal applications by noise correlation using frequency shifting [4], by optical injection locking [5], and by optical phase locking [6].…”

Frequency stability at the kilohertz level of a rubidium-locked diode laser at 192114 THz

“…4 Numerous studies have been devoted to the absolute stabilization of 1550-nm lasers. Frequency stabilization was achieved, for example, by locking to molecular lines of NH 3 , 5 C 2 H 2 , 6 HCN, 7 and HI, 8 as well as by locking to optogalvanic lines of noble gases 2,9 or to optically pumped Rb lines. 10 In most of these experiments, the locking was done to transitions whose linewidth was dominated by Doppler broadening-typically several hundred megahertz.…”

“…Single-pass doubling in a waveguide was recently used by us for locking to the Rb line 12 and the K line 15 and was also used earlier to double the 1319-nm Nd:YAG and lock the second harmonic to I 2 transitions. 18 Even though the natural linewidth of atomic lines is less than 10 MHz, the Rb and K lines are considerably narrower frequency discriminators than the Doppler-broadened lines [2][3][4][5][6][7][8] and are also narrower than the excited-state atomic transitions 9,10 at 1550 nm. Hence, we expect to obtain improved stability and reproducibility.…”