Abstract

We demonstrate that the combination of frequency controlled semiconductor lasers with inorganic and organic nonlinear optical waveguides can make a hypercoherent (FM noise below the Schawlow-Townes limit) optical sweep generator with a frequency tunable range of ~1 PHz (1 × 10¹⁵Hz), i.e., between the 1.56- and 0.34-μm wavelength region. Frequencies of two InGaAsP lasers, an AlGaAs laser, and an AlGaInP laser are controlled; for example, the half linewidth of the 0.8-μm AlGaAs laser was reduced to 560 Hz by negative electrical feedback.¹ This value is less than the Schawlow-Townes limit from which it can be said that hypercoherent state light was generated.²

© 1990 Optical Society of America