1. A motor control system for energizing a sine wave-like stairway current according to a pulse train command impressed from an external;
said motor control system comprising:
a first counting means for counting the number of steps of said pulse train command;
a latch means for holding a counting value of said first counting means with a latch signal and finding a position command;
a reference signal generating means for generating said latch signal and a reference clock signal;
a first calculating means for calculating a pulse spacing of said pulse train command with said reference clock signal; and
a second calculating means for calculating a time interval of from generation of said pulse train command to generation of said latch signal with said reference clock signal;
wherein said position command is corrected using command pulse spacing information calculated by said first calculating means and time difference information calculated by said second calculating means.
2. A motor control system according to claim 1, wherein said motor control system is designed such that said motor control system periodically carries out micro step control for a stepping motor synchronously with said latch signal.
3. A motor control system according to claim 1, wherein said motor control system is designed such that said motor control system causes a correction value of said position command to amount to zero at the time when a motor is stopped.
4. A motor control system according to claim 3, wherein said motor control system includes a second counting means for counting said reference clock signal, clearing a counting value when said pulse train command is output, and outputting an overflow signal when said counting value exceeds a predetermined value, and wherein said motor control system is designed such that said motor control system causes said correction value to amount to zero when said overflow signal is output.
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 optical resonator comprising:
an optical cavity and a phase-only optical element defining each end thereof, operable to sustain circulating laser beam therein:
wherein each phase-only optical element is operable to transform an intensity profile of a stable single mode of the laser beam without changing the mode of the laser beam during propagation along a length of the optical resonator, such that the single-mode laser beam changes its intensity profile continuously in the optical resonator while it circulates back and forth with the intensity profile of the laser beam at a first end of the optical resonator being Gaussian and with the intensity profile at a second end of the optical resonator being non-Gaussian.
2. The optical resonator as claimed in claim 1, wherein the optical resonator includes a gain medium located within the optical cavity and in which the gain medium is arranged more towards one end of the optical resonator.
3. The optical resonator as claimed in claim 2, wherein the gain medium is arranged towards the second end, for higher energy extraction than had the gain medium not been arranged towards the second end.
4. The optical resonator as claimed in claim 1, wherein the optical resonator includes an output coupling at the first end to produce an output laser beam having a Gaussian intensity profile with a lower divergence than had the intensity profile of the laser beam been constant.
5. The optical resonator as claimed in claim 1, wherein the intensity profile at the second end of the optical resonator is a Flat-Top Beam (FTB) profile.
6. A laser apparatus which includes:
the optical resonator as claimed in claim 1; and
associated drive and control circuitry to operate the optical resonator.
7. A method of generating a laser beam inside an optical resonator having a phase-only optical element defining each end thereof and operable to circulate the laser beam therein, the method including:
transforming, by means of the optical elements, an intensity profile of a stable single mode of the laser beam, without changing the mode of the laser beam during propagation along a length of the optical resonator, such that the single-mode laser beam changes its intensity profile continuously in the optical resonator while it circulates back and forth with the intensity profile of the laser beam at a first end of the optical resonator being Gaussian and with the intensity profile at a second end of the optical resonator being non-Gaussian.
8. The optical resonator as claimed in claim 5, wherein the intensity profile of the stable, single-mode laser beam between the first and second ends is a weighted average between Gaussian and Flat-Top Beam (FTB).