Abstract: A data storage device has multiple storage media surfaces and corresponding heads, each storage media surface includes multiple regions, and each head is for recording on and playback of information from a corresponding storage media surface. A method of defining a storage format for the storage media surfaces includes reading data from each region on each storage media surface with the corresponding head, measuring a record/playback performance of each head for each region on each corresponding storage media surface based on the data read from the regions, and selecting a track density for each region on each storage media surface based on the measured record/playback performance of the corresponding head for the region.

Abstract: A disk drive has multiple disk surfaces and corresponding heads, each disk surface includes multiple regions, and each head is for recording on and playback of information from a corresponding disk surface. The data track density in a first region on a first disk surface is greater than the data track density in a first region on a second disk surface, the data track density in a second region on the first disk surface is less than the data track density in a second region on the second disk surface, the first regions are radially similarly situated regions and the second regions are radially similarly situated regions.

Abstract: A method of defining storage format in a data storage device having a plurality of storage media and a plurality of corresponding data transducer heads, each transducer head for recording on and playback of information from a corresponding storage medium. A storage format is defined in at least one region on each storage medium, wherein each region includes a plurality of concentric tracks for recording on and playback of information. The method includes: moving each storage medium with respect to the corresponding transducer head and reading data from each storage medium with the corresponding transducer head; measuring a record/playback performance capability of each transducer head; selecting a group of track densities, one track density for each region on a storage medium, based on the measured record/playback performance capability of the corresponding transducer head.

Abstract: Digital control of actively mode-locked lasers where an active feedback control system is implemented to include a digital processor such as a microprocessor. The digital processor digitally extracts noise information from multiple monitor signals generated from the laser output and digitally diagnoses the operating condition of the laser based on the noise information. Based on the operating condition of the laser, the digital processor generates control signals to adjust the laser cavity to establish or regain the mode locking condition and to maintain the mode locking by reducing the output noise.

Abstract: A method of defining storage format in a data storage device having a plurality of storage media and a plurality of corresponding data transducer heads, each transducer head for recording on and playback of information from a corresponding storage medium. A storage format is defined in at least one region on each storage medium, wherein each region includes a plurality of concentric tracks for recording on and playback of information. The method includes: moving each storage medium with respect to the corresponding transducer head and reading data from each storage medium with the corresponding transducer head; measuring a record/playback performance capability of each transducer head; selecting a group of track densities, one track density for each region on a storage medium, based on the measured record/playback performance capability of the corresponding transducer head.

Abstract: Digital control of actively mode-locked lasers where an active feedback control system is implemented to include a digital processor such as a microprocessor. The digital processor digitally extracts noise information from multiple monitor signals generated from the laser output and digitally diagnoses the operating condition of the laser based on the noise information. Based on the operating condition of the laser, the digital processor generates control signals to adjust the laser cavity to establish or regain the mode locking condition and to maintain the mode locking by reducing the output noise.