Intra-cavity-modulated swept-lasers for "real-time" dispersion measurement

We have demonstrated a novel intra-cavity-modulated swept-laser (ICM-SL) for real-time dispersion measurement over a broad bandwidth. It is capable of simultaneous measurement of both the amplitude and dispersion at a record scan speed of 22 Hz over 50 nm with an effective sweep rate of 2200 nm/s. Because of the continuous-scan nature of the system, the measurement provides an analog output which is not sampling-point limited. Real-time measurement of amplitude and dispersion spectra could potentially be very useful for fast device characterization, and online monitoring during device fabrication. Furthermore, with a real-time measuring capability, it is also possible to incorporate a feedback process during device fabrication to enhance process flexibility and device performance.