Apparatus for multilevel optical recording

1. An improvement to an optical recording apparatus comprising (i) a light source, (ii) a first modulator for modulating an intensity of a light beam, (iii) a formatter, and (iv) a modulation interface, said improvement including:

an electro-optic modulator added in an optical path between the light source and the first modulator, to regulate a power of the light beam supplied to the first modulator,

wherein the formatter is adapted to supply a baseline power signal to the modulation interface and supply a formatted data signal of three or more modulation levels to the first modulator;

wherein the modulation interface is adapted to supply a power control signal to the electro-optic modulator, and the electro-optic modulator regulates the power of the light beam supplied to the first modulator to a power level corresponding to the power control level,

wherein the modulation levels include a first beam intensity corresponding to a first pit length, a second beam intensity corresponding to a second pit length, and a third beam intensity whereby a pit is not formed,

wherein at least one of the first pit length and the second pit length corresponds to less than 3T, and

wherein the apparatus is adapted by supplying the formatted data signal directly from the formatter to the first modulator, without going through the modulation interface.

2. The improved apparatus of claim 1 , wherein the apparatus is adapted for optical recording in a format using multiple modulation levels.

3. The improved apparatus of claim 1 , wherein the apparatus is adapted for cutting a glass master based on a formatted signal, and the glass master is then used for manufacturing prerecorded optical discs in a format using multiple modulation levels.

4. The improved apparatus of claim 1 , wherein the first modulator modulates the intensity of the light beam amongst multiple modulation levels based on the formatted data signal.

5. The improved apparatus of claim 1 , wherein the formatter is adapted to supply a constant-level baseline power signal to the modulation interface.

6. The optical recording apparatus of claim 1 wherein the at least one of the first pit length and the second pit length corresponds to 2T.

7. The optical recording apparatus of claim 1 wherein the at least one of the first pit length and the second pit length is configured at a rotation rate of an optical disc of at least 6.61 m/s.

8. The optical recording apparatus of claim 1 , wherein the first pit length corresponds to less than 3T and the second pit length corresponds to greater than or equal to 3T and wherein the first beam intensity is greater than the second beam intensity.

9. An optical recording apparatus for an optical recording format using multiple modulation levels, said apparatus comprising:

a light source;

a first modulator for modulating an intensity of a light beam supplied thereto, to supply a modulated beam;

an electro-optic modulator in an optical path between said light source and said first modulator, to regulate a power of the light beam supplied to the first modulator, to a power level corresponding to a power control signal;

a formatter configured to supply a baseline power signal and a formatted data signal of three or more modulation levels; and

a modulation interface configured to receive the baseline power signal from said formatter and supply the power control signal to the electro-optic modulator,

wherein the formatted data signal is supplied directly from said formatter to said first modulator, without going through said modulation interface,

wherein the modulation levels include a first beam intensity corresponding to a first pit length, a second beam intensity corresponding to a second pit length, and a third beam intensity whereby a pit is not formed,

wherein at least one of the first pit length and the second pit length corresponds to less than 3T, and

wherein said first modulator modulates the intensity of the light beam amongst multiple modulation levels based on the formatted data signal.

10. The apparatus of claim 9 further comprising a power detector, wherein said power detector detects a power of the modulated beam supplied by said first modulator and supplies to said modulation interface a power detection signal related to the detected power, and said modulation interface compares the power detection signal and an expected intensity and adjusts the power control signal based on a result of the comparison.

11. The apparatus of claim 9 , wherein the baseline power signal from said formatter is a constant-level signal.

12. A laser beam recorder comprising the apparatus of claim 9 , wherein said laser beam recorder is used for cutting a glass master based on a formatted signal, and the glass master is then used for manufacturing prerecorded optical discs in the format using multiple modulation levels.

13. A method for adapting an optical recording apparatus for optical recording formats using multiple modulation levels, said method comprising:

installing an electro-optic modulator in an optical path between a light source and a first modulator of said apparatus;

adapting a formatter of said apparatus to supply a baseline power signal and a formatted data signal of three or more modulation levels;

adapting a modulation interface of said apparatus to supply a power control signal, based on the baseline power signal, for controlling the electro-optic modulator to regulate a power of a light beam supplied to the first modulator;

connecting the formatter of said apparatus directly to the first modulator; and

supplying said formatted data signal directly to the first modulator, without going through the modulation interface,

wherein the first modulator modulates an intensity of the light beam amongst multiple modulation levels based on the formatted data signal, to supply a modulated beam,

wherein the modulation levels include a first beam intensity corresponding to a first pit length, a second beam intensity corresponding to a second pit length, and a third beam intensity whereby a pit is not formed, and

wherein at least one of the first pit length and the second pit length corresponds to less than 3T.

14. The method of claim 13 , wherein the adapted apparatus is used for cutting a glass master, and the glass master is then used for manufacturing prerecorded optical discs in a format using multiple modulation levels.

15. The method of claim 13 , wherein the baseline power signal from said formatter is a constant-level signal.

16. An optical recording method for formats using multiple modulation levels, said method comprising:

generating with a modulation interface a power control signal based on a baseline power signal from a formatter;

supplying the power control signal from the modulation interface to an electro-optic modulator installed in an optical path between a light source and a second modulator;

regulating, with the electro-optic modulator and based on the power control signal supplied from the modulation interface, a power of a light beam supplied to the second modulator;

supplying a formatted data signal of three or more modulation levels directly from said formatter to the second modulator, without going through the modulation interface; and

modulating the intensity of the light beam amongst multiple modulation levels, with the second modulator, based on the formatted data signal supplied directly from the formatter, to supply a modulated beam,

wherein the modulation levels include a first beam intensity corresponding to a first pit length, a second beam intensity corresponding to a second pit length, and a third beam intensity whereby a pit is not formed and

wherein at least one of the first pit length and the second pit length corresponds to less than 3T.

17. The method of claim 16 further comprising using the modulated beam for cutting a glass master, and using the glass master for manufacturing prerecorded optical discs in the format using multiple modulation levels.

18. The method of claim 16 , wherein the baseline power signal from said formatter is a constant-level signal.

19. The method of claim 16 further comprising:

detecting a power of the modulated beam;

supplying a power detection signal related to the detected power;

comparing the power detection signal and an expected intensity; and

adjusting the power control signal based on a result of the comparison.