What is claimed is:
1. A high density magnetic recording medium, which has a uniform local coercivity distribution and grain size distribution, and fine grains, comprising:
a CoCrPt alloy thin film including the (Co82Cr18)100-xPtx alloy thin film containing 1 to 14 atom % Pt; and
a Ti thin film positioned under the (Co82Cr18)100-xPtx alloy thin film.
2. The high density magnetic recording medium as set forth in claim 1, wherein the (Co82Cr18)100-xPtx alloy thin film and the Ti thin film are respectively 400 and 1100 in thickness.
3. A high density magnetic recording medium using a CoCrPt alloy thin film, which has a uniform local coercivity distribution and grain size distribution, and fine grains, comprising:
a glass substrate;
a Ti thin film layered on the glass substrate;
a (Co82Cr18)100-xPtx alloy thin film containing 1 to 14 atom % Pt and deposited on the Ti thin film; and
a Si3N4 thin film deposited on the (Co82Cr18)100-xPtx alloy thin film.
4. The high density magnetic recording medium as set forth in claim 3, wherein the (Co82Cr18)100-xPtx alloy thin film, the Ti thin film, and the Si3N4 thin film are respectively 400, 1100, and 500 in thickness.
5. A method of manufacturing a high density magnetic recording medium which has a uniform local coercivity distribution and grain size distribution, and fine grains, comprising:
a first step of layering a Ti thin film on a glass substrate;
a second step of depositing a CoCrPt alloy thin film on the Ti thin film, the CoCrPt alloy thin film containing a predetermined composition of Pt controlled by a CoCr alloy target having a Pt chip positioned thereon; and
a third step of depositing Si3N4 on the CoCrPt alloy thin film.
6. The method as set forth in claim 5, wherein the second step is conducted under sputtering pressure of 3 mtorr at room temperature, and the CoCrPt alloy thin film is deposited on the Ti thin film in a deposition rate of 14 s.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An efficient oscillator comprising:
an optical modulator having an optical phase shifter; and
a feedback path including an optical section and an electronic section, said electronic section providing electrical modulation input to said optical modulator.
2. The system of claim 1 wherein said optical phase shifter is a controllable optoelectronic phase shifter responsive to control signals from a controller.
3. The system of claim 2 wherein said optoelectronic phase shifter is an optical Radio Frequency (RF) phase shifter, and wherein said electronic section is an RF section.
4. The system of claim 3 wherein said optical phase shifter is positioned within said oscillator so that changes in phase applied to an optical signal output from said optical modulator by said optical phase shifter yield changes in frequency of an optical signal output by said efficient oscillator.
5. The system of claim 4 wherein said optical section including an optical delay line and a photo detector, said photo detector providing said RF signal to said RF section in response thereto.
6. The system of claim 5 wherein said RF section includes an RF filter, an RF amplifier, and an RF coupler that couples RF energy to said optical modulator, said optical modulator employing said RF energy to modulate an RF signal on an optical carrier signal, said optical carrier signal input to said optical modulator from an external source.
7. The system of claim 6 wherein said external source includes a laser.
8. The system of claim 2 wherein said efficient oscillator is a frequency-tunable optoelectronic oscillator that includes means for modulating a desired signal on an optical carrier signal.
9. The system of claim 8 wherein said desired signal is an RF signal.
10. The system of claim 9 wherein said means for modulating includes a phase-shifting optical modulator exhibiting a nested Mach-Zehnder configuration.
11. The system of claim 8 wherein said optical oscillator includes an optical feedback signal that passes through a delay line and to a detector, said detector converting said optical feedback signal to a radio frequency feedback signal that is fed back to an optical modulator of said optical oscillator.