Abstract: A miniature, fiber-coupled Fabry-Perot interferometer has a piezoelectric transducer coupled to first and second collimating lenses. The collimating lenses collimate and interfere light energy within a gap formed between the lenses as part of the interferometer. Preferably, the lenses are matched mode gradient index lenses. Light energy coupled to the collimating lens is thus collimated and interfered within the gap. The piezoelectric transducer expands or contracts to adjust the gap, thereby adjusting the free spectral range of the interferometer. An input fiber provides input to the interferometer; an output fiber carries processed light energy of the selected free spectral range to external devices and optical systems. Metal coatings may be used to provide a capacitive feedback of lens position to calibrate the gap and, thus, the free spectral range.

Abstract: A miniature, fiber-coupled Fabry-Perot interferometer has a piezoelectric transducer coupled to first and second collimating lenses. The collimating lenses collimate and interfere light energy within a gap formed between the lenses as part of the interferometer. Preferably, the lenses are matched mode gradient index lenses. Light energy coupled to the collimating lens is thus collimated and interfered within the gap. The piezoelectric transducer expands or contracts to adjust the gap, thereby adjusting the free spectral range of the interferometer. An input fiber provides input to the interferometer; an output fiber carries processed light energy of the selected free spectral range to external devices and optical systems. Metal coatings may be used to provide a capacitive feedback of lens position to calibrate the gap and, thus, the free spectral range.

Abstract: The present invention provides a back-up tape drive having a precision molded chassis with a fine positioning system for a tape head. This system includes a follower nut threadingly mounted on a lead screw that is bi-directionally rotated by a stepper motor. A lever arm engages the follower nut in a manner such that torsional moments between the forces of the follower nut and lever arm are minimized. The other end of the lever arm engages a tape head mounting unit. The lever arm pivotally engages the chassis at a predetermined midpoint of the lever arm such that a mechanical advantage is derived. The positioning system is designed so the forces acting on the tape head mounting unit are aligned to minimize the torsional forces acting on the tape head mounting unit. The tape head mounting unit further includes reference features that reduce the need for azimuth and zenith adjustment.

Abstract: A computer memory backup device which utilizes magnetic tape media having aperture indications at the beginning-of-tape (bot) and the end-of-tape (eot) for accomplishing the sensing of the same is disclosed. The present invention utilizes a light pipe for directing the emitted electromagnetic radiation from an isolated source to the magnetic tape media, and focuses the radiation in proximity to the media. An integral focusing lens disposed on the exit end of the light pipe serves to converge the exiting electromagnetic radiation in this fashion. The electromagnetic radiation source, shown as a light emitting diode, is pulsed in a manner such that accuracy, as well as energy conservation, is greatly increased. A time domain filtering method is employed as a means to further enhance the system's accuracy in sensing the beginning-of-tape and end-of-tape. The devices accommodate standard aperture indications as required by ANSI specifications in both dimensional and placement aspects.

Abstract: Apparatus is disclosed for using a head having narrow write gap to write tracks of information on a tape for subsequent reading by other apparatus including apparatus having heads with a wide read gap. An inter track erase operation is performed prior to the writing operation. Density information is written on a plurality of tracks to indicate the flux reversal signal density used for the writing of user data elsewhere on the tape.