Experimental investigation of domain expansion speeds in MAMMOS

Summary form only given. Since high data rates are critical to the success of MAMMOS (magnetically amplified magneto-optical disc system) technology, expansion and collapse speeds of magnetic domains have become a topic of recent interest. To date, the expansion speed in a MAMMOS system has not been directly measured. One way to measure the speed, is by observing the rise and fall times of the magneto-optic readback signal and inferring wall velocities from these times. To measure the rise and fall times experimentally, a MAMMOS system with a 658 nm laser and 0.6 NA lens was equipped with a high-speed photo detector recently developed at Philips. Using this system, MAMMOS readout signals were collected for various laser powers and readout fields using a LaCroy DDA-110 to sample the photo detector output at 2 GHz.