Apparatus and Method for the Generation of Supercontinuum Pulses

An optical pulse source, for generating optical supercontinuum pulses at a repetition rate, comprising:

• an optical pump laser operable to generate a number of optical pump pulses at a pump pulse repetition rate;
• a nonlinear optical element arranged to receive the optical pump pulses and configured to generate therefrom optical supercontinuum pulses;
• a gating device provided between the pump laser and the nonlinear optical element and operable to selectively limit the number of optical pump pulses received by the nonlinear optical element in order to generate optical supercontinuum pulses at a user selectable repetition rate lower than the pump pulse repetition rate;
• and
• wherein the optical pulse source further comprises a second gating device provided after the nonlinear optical element.

A method of allowing a user to select the repetition rate of generating optical supercontinuum pulses generated by a source of optical supercontinuum pulses, comprising:

• generating a number of optical pump pulses having an associated repetition rate and a duration with a pump pulse source;
• gating the optical pump pulses to reduce the repetition rate;
• introducing the gated optical pump pulses into a nonlinear optical element and generating therefrom optical supercontinuum pulses at the reduced repetition rate, wherein the user can select the reduced repetition rate;
• where the optical supercontinuum pulses have an associated energy, and the method further comprises
• scaling the optical supercontinuum pulse energy by increasing the pump pulse duration as well as reducing the pump pulse repetition rate of the optical pump laser.

An optical pulse source for generating optical supercontinuum pulses at a repetition rate, comprising:

• an optical pump laser operable to generate a number of optical pump pulses at a pump pulse repetition rate;
• a nonlinear optical element arranged to receive the optical pump pulses and configured to generate therefrom optical supercontinuum pulses;
• a gating device provided between the pump laser and the nonlinear optical element and operable to selectively limit the number of optical pump pulses received by the nonlinear optical element in order to generate optical supercontinuum pulses at a user selectable repetition rate lower than the pump pulse repetition rate;
• and
• wherein the optical pulse source is configured to generate output optical supercontinuum pulses at a repetition rate in the range 1 MHz to 10 MHz with an energy spectral density of at least 100 picojoules per nanometer, and the optical pulse source is configured to provide an illumination source for a stimulated emission depletion (STED) microscope.

A method of allowing a user to select the repetition rate of optical supercontinuum pulses generated by a source of optical supercontinuum pulses, comprising:

• generating a number of optical pump pulses having an associated repetition rate and a duration with a pump pulse source;
• gating the optical pump pulses to reduce the repetition rate;
• introducing the gated optical pump pulses into a nonlinear optical element and generating therefrom optical supercontinuum pulses at the reduced repetition rate wherein the user can select the reduced repetition rate;
• and
• the method further comprising making use of the optical supercontinuum pulses to perform fluorescent lifetime imaging (FLIM), time correlated fluorescence single photon counting (TCSPC), or stimulated emission depletion (STED) microscopy.

A method of generating optical supercontinuum pulses having increased spectral energy density, comprising:

• generating a number of optical pump pulses having an associated repetition rate;
• gating the optical pump pulses to reduce the repetition rate;
• amplifying the gated optical pump pulses with an optical fiber amplifier wherein the pulse energy is fixed;
• and
• introducing the amplified and gated optical pump pulses into a nonlinear optical element and generating therefrom optical supercontinuum pulses at the reduced repetition rate.