The present invention provides a low-loss high-repetition-rate pulsed laser modulator comprising: a 2*2, 1:1 coupler; a light delay module; a 1*2, 1:1 coupler. The present invention can modulate a low-repetition-rate pulsed laser to be a high-repetition-rate pulsed laser. The basic principle is: one beam of low-repetition-rate pulsed laser can be divided into two beams with the same light intensity by a 1*2, 1:1 coupler; control the two beams of light to have an optical path difference so that when they are coupled into a 2*2, 1:1 coupler, a double pulse repetition rate can be obtained; In the same way, when the two beams of light from former 2*2, 1:1 coupler, with another different optical path difference are coupled into the next 2*2, 1:1 coupler, a double pulse repetition rate can be obtained again; when we obtain the repetition rate we need, a 1*2, 1:1 coupler instead is connected to couple the two beams of light into one beam with a double repetition rate.

An annular optical shifter and a method for controlling shift, where the annular optical shifter includes: a first bent straight-through waveguide, connecting an input end and an output end of an optical signal, and configured to transmit, to the output end, the optical signal input from the input end; multiple optical delay waveguide loops, arranged transversely and parallel on two arms of the first bent straight-through waveguide, where the multiple optical delay waveguide loops are configured to temporarily store optical signals; multiple pairs of optical switches, where each pair of optical switches are configured to control on and off of an optical path that is on the two arms of the first bent straight-through waveguide and two sides of an optical delay waveguide loop corresponding to each pair of optical switches; and a controller, configured to implement shift-up or shift-down of the optical signals.

The present invention provides a low-loss high-repetition-rate pulsed laser modulator comprising: a 2*2, 1:1 coupler; a light delay module; a 1*2, 1:1 coupler. The present invention can modulate a low-repetition-rate pulsed laser to be a high-repetition-rate pulsed laser. The basic principle is: one beam of low-repetition-rate pulsed laser can be divided into two beams with the same light intensity by a 1*2, 1:1 coupler; control the two beams of light to have an optical path difference so that when they are coupled into a 2*2, 1:1 coupler, a double pulse repetition rate can be obtained; In the same way, when the two beams of light from former 2*2, 1:1 coupler, with another different optical path difference are coupled into the next 2*2, 1:1 coupler, a double pulse repetition rate can be obtained again; when we obtain the repetition rate we need, a 1*2, 1:1 coupler instead is connected to couple the two beams of light into one beam with a double repetition rate.

A light source including: a pulse generator for providing a first sequence of light pulses, the first sequence of light pulses including a first number of light pulses within a predetermined time period, a manipulator configured to generate a second sequence of light pulses from the first sequence of light pulses, the second sequence of light pulses having a second number of light pulses within the predetermined time period, the second number being different from the first number, and a nonlinear optical element arranged to receive the second sequence of light pulses.

A cascaded harmonic generator, for cascaded optical harmonic generation from an optical beam provided by a laser source, may include a second harmonic generator to generate a second harmonic optical beam based on a residual beam associated with the optical beam. The cascaded harmonic generator may include a third harmonic generator to generate a third harmonic optical beam based on the second harmonic optical beam and the optical beam. The third harmonic generator may be positioned in an optical path upstream from the second harmonic generator. A harmonic generator delay time, associated with the optical path, may be approximately equal to, or may be an approximate integer multiple of, a laser source round-trip time.

A light source including: a pulse generator for providing an initial sequence of light pulses, the pulse generator including an optical source for producing optical pulses; a modulator in communication with the optical source for increasing or decreasing the selected number of pulses provided by the pulse generator in the selected time period; first and second optical arms, for propagating, respectively, first and second sequences of light pulses, wherein the first optical arm includes a first manipulator configured to generate the first sequence of light pulses from the initial sequence of light pulses, wherein the light source includes a nonlinear optical element arranged to receive the first sequence of light pulses or the second sequence of light pulses, and an optical switch arranged to switch either the first sequence of light pulses or the second sequence of light pulses for reception by the nonlinear optical element.

It includes a first optical intensity modulator (2) that outputs an optical pulse in which the signal intensity of photocarriers output from a light source (1) is modulated in accordance with the magnitude of a first drive signal around an operation bias point , a delay unit (3) that generates a second drive signal obtained by delaying the first drive signal by a half cycle, and a second optical intensity modulator (4) that outputs an optical short pulse in which the signal intensity of the optical pulse is modulated in accordance with the magnitude of the second drive signal around an operation bias point.

An optical device includes a first plurality of waveguides including a first waveguide and a second waveguide and a multimode waveguide delay comprising a first end and a second end. The first waveguide and the second waveguide are coupled to the first end of the multimode waveguide delay. The first waveguide is coupled to a first optical mode in the multimode waveguide delay. The second waveguide is coupled to a second optical mode in the multimode waveguide delay. The optical device includes a second plurality of waveguides including a third waveguide and a fourth waveguide. The third waveguide and the fourth waveguide are coupled to the second end of the multimode waveguide delay. The third waveguide is coupled to the first optical mode in the multimode waveguide delay. The fourth waveguide is coupled to the second optical mode in the multimode waveguide delay.

Structures for a modulator and methods of forming a structure for a modulator. The structure comprises a first waveguide core including a delay section, and a second waveguide core including a delay section. The delay section of the second waveguide core has a shorter length than the delay section of the first waveguide core. The structure further comprises an optical phase shifter including a p-n junction in a portion of the delay section of the first waveguide core.

A generator device for generating an arbitrary optical pulse pattern includes: a light source to provide primary laser pulses, a distributor to provide a plurality of primary optical pulses by distributing light of the primary laser pulses (LB00.sub.k) into a plurality of branches, a combiner to form an output signal by combining modulated optical signals from the branches, and a controller unit to provide control signals for controlling optical modulators of the branches, wherein a first branch comprises a first optical modulator to form a first modulated optical signal from primary optical pulses of the first branch, wherein a second branch comprises a second optical modulator to form a second modulated optical signal from primary optical pulses of the second branch, and wherein a propagation delay of the second branch is different from a propagation delay of the first branch.