Fiber assembly for all-fiber delivery of high energy femtosecond pulses

A chirped pulse amplification system, comprising:

• a pulse source;
• a first fiber section for stretching pulses from the pulse source, the first fiber section comprising a high order mode fiber;
• a second fiber section for compressing the stretched pulses, connected to the first fiber section via a splice, the second fiber section comprising a hollow core photonic bandgap fiber;
• and
• at least one amplification stage between the first fiber section and the second fiber section;
• wherein the high order mode fiber comprises a negative dispersion and negative dispersion slope at about 800 nm or at about 1000 nm, and wherein the relative dispersion slope of the high order mode fiber is substantially the same as the relative dispersion slope of the photonic bandgap fiber.

A method of providing an all-fiber delivery of high energy femtosecond pulses, comprising:

• providing an all-fiber assembly comprising:
• a first fiber section for stretching pulses received from a pulse source, the first fiber section comprising a high order mode fiber;
• and
• a second fiber section for compressing the stretched pulses, connected to the first fiber section via a splice, the second fiber section comprising a hollow core photonic bandgap fiber;
• generating an input pulse from the pulse source into the all-fiber assembly;
• and
• receiving an output pulse compression at less than 200 fs from the all-fiber assembly.

A method of compensating dispersion of a photonic bandgap fiber in a fiber assembly comprising:

• obtaining the dispersion characteristics of a photonic bandgap fiber at a frequency;
• obtaining the relative dispersion slope of the photonic bandgap fiber from the dispersion characteristics;
• matching the relative dispersion slope of the photonic bandgap fiber with a relative dispersion slope of a high order mode fiber;
• and
• coupling the photonic bandgap fiber with the high order mode fiber.