Broadband light source device and method of creating broadband light pulses

A method of creating broadband light pulses, the method comprising:

• coupling pump laser pulses into a hollow-core photonic crystal fiber of non-bandgap type including a filling gas, wherein the hollow-core photonic crystal fiber comprises:
• a hollow core configured to support core modes of a guided light field;
• and
• a ring of capillaries surrounding the hollow core and configured to support transverse wall modes of the guided light field;
• and
• creating broadband light pulses by an optical non-linear broadening of the pump laser pulses in the hollow-core photonic crystal fiber,
• wherein a wall thickness of the ring of capillaries is in a range from 70 nm to 150 nm.

A broadband light source comprising:

• a gas cell comprising a filling gas and an input window configured to receive pump laser pulses;
• and
• a hollow-core photonic crystal fiber of non-bandgap type at least partially enclosed within the gas cell and configured to create broadband light pulses, the hollow-core photonic crystal fiber comprising:
• a hollow core configured to support core modes of a guided light field;
• and
• a ring of capillaries surrounding the hollow core and configured to support transverse wall modes of the guided light field,
• wherein a wall thickness (t) of the ring of capillaries is such that
• t
• <
• λ
• min
• 2
• ⁢
• n
• 2
• 2
• -
• n
• 1
• 2
• wherein λmin is a shortest wavelength of a core mode spectrum, n1 is a refractive index of the filling gas in the hollow-core photonic crystal fiber, and n2 is a refractive index of the ring of capillaries.