Intracavity Fabry-Perot-modulator: Characterization and modelling

Summary form only given. Modulation of intracavity losses is a powerful tool for controlling the laser dynamics, e.g. for active mode-locking and for synchronization of different lasers. In this paper we present an optical device that allows for fast modulation of the intracavity losses by external illumination. The device is designed as a nonlinear semiconductor Fabry-Perot etalon consisting of two Bragg reflectors with a center wavelength of 1064 nm at the backside and the frontside of a 5-/spl mu/m-thick nonlinear medium - an InGaAs layer. The indium content is chosen such that the bandgap energy is 1.28 eV (/spl lambda//sub gap/ = 970 nm). While the device is highly reflecting for wavelengths longer than /spl lambda//sub gap/ around 1064 nm, radiation with /spl lambda/ < /spl lambda//sub gap/ generates carriers which change the index of refraction and, therefore, the reflectivity of the device in the vicinity of a Fabry-Perot resonance. To characterize the capabilities of the optically controlled Fabry-Perot-modulator (FPM), we performed a spectrally resolved two color pump probe measurement.