Higher-Order Distributed Feedback Oscillators

Abstract

We report the observation of higher‐order disftributed‐feedback (DFB) laser oscillation using sinusoidal susceptibility modulation. For higher‐order DFBoscillation the period of the susceptibility modulation is a multiple m of one‐half the lasing wavelength. We have obtained tunable DFBoscillation for m=2 and m=3 by pumping rhodamine 6G with interference fringes. A discussion of two possible mechanisms which could account for our observations is presented. Higher‐order DFB operation reduces the resolution required for fabricating a DFB laser.