Abstract: A method and apparatus are provided for modulating a laser beam with an information signal. The method includes the steps of modulating a plurality of coherent, optical signals with a respective information signal of the plurality of information signals and directing the modulated optical signals onto a photodiode. The method further includes the steps of detecting the collected signals in the photodiode and refractively synchronizing the laser beam with clock reference signals which allow easy separation of the modulated signal blocks at the receiving end of the fiber optic.

Abstract: A method and apparatus are provided for modulating a coherent light source with a digital) signal. The method includes the steps of splitting the digital signal into a first and a second copy and mixing the first copy with a clock signal to provide a first modulation component. The method further includes the steps of inverting the second copy and delaying the clock signal by one-hundred eighty degrees. The method also includes the steps of mixing the inverted second copy with the delayed clock signal to provide a second modulation component and summing the first and second modulation components.

Abstract: A method and apparatus are provided for stabilizing a distributed feedback semiconductor laser. The method includes the steps of comparing an optical output of a first oscillating mode of the semiconductor laser at a first polarization angle with an optical output of a second oscillating mode of the semiconductor laser at a second polarization angle orthogonal to the first polarization angle. A first feedback signal is provided to a cavity temperature controller of the semiconductor laser in response to detected differences of the compared first and second oscillating modes. The method further includes the step of comparing an output of the reference laser with an output of the semiconductor laser and providing a difference signal as a second feedback signal to the temperature controller of the semiconductor laser in response to detected differences between the reference laser and semiconductor laser.