Analog compensation system for linear lasers

Claim 2

An error compensation system comprising: a first laser; modulation means coupled to the first laser for providing an output signal to drive the first laser to cause it to emit modulated light; an optical fiber disposed to receive light from the first laser; tap means coupled to the optical fiber for removing a desired amount of light from the optical fiber; sensing means disposed in proximity to the tap for detecting the light removed from the optical fiber and in response providing a first signal; comparator means connected to the sensing means to receive the first signal and connected to the modulation means to receive the output signal, and in response thereto provide an error correction signal; a second laser connected to receive the error correction signal and in response emit modulated light; and summing means connected to receive the light from the second laser and combine it with light from the first laser on the optical fiber; and detector means coupled to the summing means to receive the combined light from the first and second laser and to generate an output signal with the desired modulation without the distortions.

Claim 3

A system as in claim 1 further comprising a first delay line connected to the comparator means and connected to the modulation means for receiving the output signal therefrom and delaying the output signal before supplying it to the comparator means.

Claim 4

A system as in claim 2 further comprising a second delay line connected between the tap means and the summing means for delaying the light therebetween.

Claim 5

A system as in claim 3 wherein: the output signal is an electronic signal; and the first delay line comprises a elongated electrical conductor.

Claim 6

A system as in claim 4 wherein the second delay line comprises an elongated optical fiber.

Claim 7

A system as in claim 1 wherein the comparator means comprises: amplifier means for comparing the first signal and the output signal and in response providing a difference signal indicative of the difference between the first signal and the output signal; and inverting means connected to the amplifier means for inverting the difference signal and providing a resulting inverted difference signal to the second laser.

Claim 8

A system as in claim 1 wherein the tap means comprises a tap for the optical fiber which tap removes a lesser portion of the light therein without affecting a greater portion remaining.

Claim 9

A system as in claim 7 wherein the tap means comprises a fused biconic tap.

Claim 10

A system as in claim 7 wherein the tap means comprises a bend type coupler.

Claim 11

A system as in claim 1 wherein: the first laser comprises a high power laser; and the second laser comprises a low power laser.

Claim 12

A system as in claim 10 wherein: the high power laser comprises a distributed feedback linear laser; and the low power laser comprises a Fabry Perot laser.

Claim 13

A system as in claim 1 wherein the modulation means comprises an amplitude modulator.

Claim 14

A system as in claim 12 wherein the amplitude modulator comprises a modulator for one or more television channels.

Claim 15

A system as in claim 1 wherein the sensing means comprises a photodetector.

Claim 16

A system as in claim 1 further comprising means for predistorting the output signal from the modulation means.

Claim 17

An error compensation system for one or more television signals being transmitted over an optical fiber comprising: a first high power laser; an amplitude modulator coupled to the first laser for providing a television signal to drive the first laser to cause it to emit modulated light; an elongated electrical conductor delay line connected to the amplitude modulator for receiving the television signal therefrom and delaying it; an optical fiber disposed to receive light from the first laser; a tap coupled to the optical fiber spaced apart from the first laser along the optical fiber for removing a desired amount of light from the optical fiber; a photodetector disposed in proximity to the tap for detecting the light removed from the optical fiber and in response providing a first signal; a summing amplifier connected to the photodetector to receive the first signal and connected to the electrical conductor to receive the television signal for comparing the first signal and the television signal and in response providing a difference signal indicative of the difference between the first signal and the television signal; a second low power laser connected to receive the difference signal and in response emit light; an elongated optical fiber delay line connected to the tap for delaying the light not removed from the optical fiber; and a second tap connected to fiber delay line to receive the light from the second laser and combine it with light from the first laser on the optical fiber; and detector means coupled to the summing means to receive the combined light from the first and second laser and to generate an output signal with the desired modulation without the distortions.

Claim 18

An error compensation system for one or more television signals being transmitted over an optical fiber comprising: a first high power laser; an amplitude modulator coupled to the first laser for providing a television signal to drive the first laser to cause it to emit modulated light; an elongated electrical conductor delay line connected to the amplitude modulator for receiving the television signal therefrom and delaying it; an optical fiber disposed to receive light from the first laser; a tap coupled to the optical fiber spaced apart from the first laser along the optical fiber for removing a desired amount of light from the optical fiber; a photodetector disposed in proximity to the tap for detecting the light removed from the optical fiber and in response providing a first signal; a summing amplifier connected to the photodetector to receive the first signal and connected to the electrical conductor to receive the television signal for comparing the first signal and the television signal and in response providing a difference signal indicative of the difference between the first signal and the television signal; a second low power laser connected to receive the difference signal and in response emit light; an elongated optical fiber delay line connected to the tap for delaying the light not removed from the optical fiber; and a second tap connected to fiber delay line to receive the light from the second laser and combine it with light from the first laser on the optical fiber; and detector means coupled to the summing means to receive the combined light from the first and second laser and to generate an output signal with the desired modulation without the distortions.

Claim 19

A system as in claim 16 wherein: the high power laser comprises a distributed feedback linear laser; and the low power laser comprises a Fabry Perot laser.