Dispersion compensation circuitry and system for analog video transmission with direct modulated laser

A phase shifter comprising:

• an input port for receiving an input signal;
• a splitter having an input connected to the input port and having first and second outputs, the splitter delivering at least three times the signal power level to the first output as it delivers to the second output;
• a combiner having first and second inputs and further having an output for carrying a phase shifted version of the input signal;
• a first signal path connecting the first output of the splitter to the first input of the combiner;
• and
• a second signal path connecting the second output of the splitter to the second input of the combiner, the second signal path including a variable attenuator and an all-pass network having an input and a first output, the input and first output of the all-pass network being connected in series combination with the variable attenuator, wherein the all-pass network provides on its first output a version of the signal on its input which is shifted in phase by a phase angle φ+90°, where 0<φ<90°.