An optical pulse generator comprising an optical frequency comb generator, the optical frequency comb generator comprising: a waveguide part comprising an optical input part, a branching part for branching light from the optical input part, a first waveguide through which light branched by the branching part propagates, a second waveguide through which other light branched by the branching part propagates, a multiplexing part for multiplexing optical signals output from the first waveguide and the second waveguide, and an optical signal output part for outputting optical signals multiplexed by the multiplexing part; a drive signal system for obtaining a first drive signal for driving the first waveguide and a second drive signal for driving the second waveguide; and a bias signal system for obtaining bias signals (12,13) applied to the first waveguide and the second waveguide, wherein the first drive signal and the second drive signal are obtained from one drive signal system, wherein the length l 1 of a first modulated electrode provided along the first waveguide and the length l 2 of a second modulated electrode provided along the second waveguide are different from each other, wherein the drive signal system and the bias signal system drive the first drive signal, the second drive signal and the bias signals (12,13) in accordance with the following Formula: ΔA ± Δθ = π/2 wherein ΔA and Δθ are defined, respectively, as ΔA≡(A 1 -A 2)/2 and Δθ≡(θ 1 -θ 2)/2, and A 1 and A 2 indicate, respectively, optical phase shift amplitudes induced by the first drive signal and the second drive signal when input into the electrodes, and θ 1 and θ 2 indicate, respectively, optical phase shift amounts induced by optical length differences and bias signals within the first waveguide and the second waveguide, wherein the drive signal system inputs the second drive signal into the second modulated electrode, and the second drive signal output from the second modulated electrode is input into the first modulated electrode as the first drive signal; the optical pulse generator further comprising a bandpass filter into which output from the optical frequency comb generator is input, and a distributed fiber, wherein the distributed fibre is a single mode fibre with a negative wavelength dispersion, into which output from the bandpass filter is input. a waveguide part comprising an optical input part, a branching part for branching light from the optical input part, a first waveguide through which light branched by the branching part propagates, a second waveguide through which other light branched by the branching part propagates, a multiplexing part for multiplexing optical signals output from the first waveguide and the second waveguide, and an optical signal output part for outputting optical signals multiplexed by the multiplexing part; a drive signal system for obtaining a first drive signal for driving the first waveguide and a second drive signal for driving the second waveguide; and a bias signal system for obtaining bias signals (12,13) applied to the first waveguide and the second waveguide, wherein the first drive signal and the second drive signal are obtained from one drive signal system, wherein the length l 1 of a first modulated electrode provided along the first waveguide and the length l 2 of a second modulated electrode provided along the second waveguide are different from each other, wherein the drive signal system and the bias signal system drive the first drive signal, the second drive signal and the bias signals (12,13) in accordance with the following Formula: ΔA ± Δθ = π/2 wherein ΔA and Δθ are defined, respectively, as ΔA≡(A 1 -A 2)/2 and Δθ≡(θ 1 -θ 2)/2, and A 1 and A 2 indicate, respectively, optical phase shift amplitudes induced by the first drive signal and the second drive signal when input into the electrodes, and θ 1 and θ 2 indicate, respectively, optical phase shift amounts induced by optical length differences and bias signals within the first waveguide and the second waveguide, wherein the drive signal system inputs the second drive signal into the second modulated electrode, and the second drive signal output from the second modulated electrode is input into the first modulated electrode as the first drive signal; the optical pulse generator further comprising a bandpass filter into which output from the optical frequency comb generator is input, and a distributed fiber, wherein the distributed fibre is a single mode fibre with a negative wavelength dispersion, into which output from the bandpass filter is input.