Patent ID: 8326097

Claim:
A Hermite Gaussian (HMG) optical launch apparatus for optically launching laser light into a multimode optical fiber (MMF) to excite an identified higher-order mode group of the MMF, the HMG optical launch apparatus comprising: a laser for producing laser light; at least one optical element positioned to receive laser light produced by the laser, said at least one optical element being configured to focus the received laser light to at least one waist; a linear phase mask positioned at a location where the laser light produced by the laser is focused to a waist by said at least one optical element and directed onto the linear phase mask, the linear phase mask being configured with a phase pattern that causes a phase of the laser light directed onto the linear phase mask to be altered to match or substantially match a phase of an identified higher-order HMG mode of the MMF; and wherein the laser, said at least one optical element, and the linear phase mask are positioned relative to each other and relative to an entrance facet of the MMF such that the phase-altered laser light has a waist at the entrance facet of the MMF that matches or substantially matches a waist of said identified higher-order mode of the MMF, and wherein the phase-altered laser light that is incident on the entrance facet of the MMF causes the identified higher-order mode group to which the identified HMG mode belongs to be excited, and wherein the excitation of the identified higher-order mode group causes a modal bandwidth of the MMF to be increased.