Optical Beam Timing Monitor Experiments at the Advanced LightSource

We present the initial results of an experimental study of abeam timing monitor based on an optoelectronic technique. This techniqueuses the electrical signal from a beam position monitor to modulate theamplitude of a train of laser pulses, converting timing jitter into anamplitude jitter. This modulation is then measured with a photodetectorand sampled by a fast ADC. This approach has already demonstrated sub-100fs resolution and promises even better results. Additionally, we areplanning to use the technique as a way to extract the maximum possiblebandwidth from a BPM, avoiding the dispersion typical of long RF cables.We show our initial results using signals from the Advanced Light Sourcestorage ring