The line narrowed laser apparatus configured to perform a plurality of burst oscillations including a first burst oscillation and a second burst oscillation next to the first burst oscillation to output a pulse laser beam. The line narrowed laser apparatus comprises a laser resonator, a chamber provided in the laser resonator, a pair of electrodes provided in the chamber, an electric power source configured to apply pulsed voltage to the pair of electrodes, a wavelength selecting element provided in the laser resonator, a spectral width varying unit provided in the laser resonator, and a controller. The controller is configured to measure a duty in a predetermined period before starting the second burst oscillation and a length of a suspension period from a time of ending the first burst oscillation to a time of starting the second burst oscillation, and perform a first control of the spectral width varying unit based on the duty and the length of the suspension period.

A frequency stabilizer includes: a delay line interferometer that receives an optical signal corresponding to one frequency mode of a pulsed laser, divides and transmits the received optical signal to a reference arm and a delay arm including an optical fiber delay line, and then outputs an interference signal between signals passing through the reference arm and the delay arm; a photoelectric converter that converts the interference signal into an electrical signal; a mixer that generates a baseband signal of the electrical signal by mixing a carrier frequency signal; and a feedback controller that transmits a control signal generated based on the baseband signal to the pulsed laser. The optical signal passing through the delay arm is weighted with a delay time caused by the optical fiber delay line compared to the optical signal passing through the reference arm, and the optical signal passing through the delay arm is frequency shifted to a carrier frequency of an oscillator. A carrier-envelope offset frequency of the pulsed laser is stabilized by an offset frequency stabilizer.

A multi-wavelength laser is provided, including a reference wavelength-tunable laser, N?1 secondary wavelength-tunable lasers, N beam splitters, a phase modulator, and N?1 frequency difference detection apparatuses. The reference wavelength-tunable laser is connected to one beam splitter which includes two output ports, and one of the output ports is connected to the phase modulator. The phase modulator is separately connected to the N?1 frequency difference detection apparatuses. The N?1 secondary wavelength-tunable lasers one-to-one correspond to remaining N?1 beam splitters and the N?1 frequency difference detection apparatuses. The secondary wavelength-tunable laser is connected to a corresponding beam splitter, the corresponding beam splitter includes two output ports, and one of the output ports is connected to a corresponding frequency difference detection apparatus. N is a positive integer not less than 2. A multi-wavelength optical signal generated by the phase modulator has a precise frequency spacing.

A laser transmitter is provided that includes a seed signal generator, an amplitude modulator and a power amplifier. The seed signal generator is configured to generate a seed signal that has a continuous waveform. The amplitude modulator is configured to generate a flat-top pulse signal based on the seed signal. The power amplifier is configured to generate a laser output signal based on the flat-top pulse signal.

The present invention relates to a wavelength locking structure for a tunable laser and a wavelength locking method for a tunable laser. According to the present invention, since it is possible to use only one element for measuring the intensity of light, the number of parts is reduced in comparison to methods of the related art, so it is possible to perform wavelength locking economically with a down-sized structure.

A laser transmitter is provided that includes a seed signal generator, an amplitude modulator and a power amplifier. The seed signal generator is configured to generate a seed signal that has a continuous waveform. The amplitude modulator is configured to generate a flat-top pulse signal based on the seed signal. The power amplifier is configured to generate a laser output signal based on the flat-top pulse signal.

The disclosure provides an optical module, including a laser, the laser including a light emitting region and a modulation region, and light emitted by the light emitting region emitting toward the modulation region; a first driver circuit, the first driver circuit being connected to the light emitting region, so that the light emitting region emits light with adjusted optical power; and a second driver circuit, the second driver circuit being connected to the modulation region, so that the modulation region changes the optical power of the light emitted from the light emitting region.

The line narrowed laser apparatus configured to perform a plurality of burst oscillations including a first burst oscillation and a second burst oscillation next to the first burst oscillation to output a pulse laser beam. The line narrowed laser apparatus comprises a laser resonator, a chamber provided in the laser resonator, a pair of electrodes provided in the chamber, an electric power source configured to apply pulsed voltage to the pair of electrodes, a wavelength selecting element provided in the laser resonator, a spectral width varying unit provided in the laser resonator, and a controller. The controller is configured to measure a duty in a predetermined period before starting the second burst oscillation and a length of a suspension period from a time of ending the first burst oscillation to a time of starting the second burst oscillation, and perform a first control of the spectral width varying unit based on the duty and the length of the suspension period.

The disclosure provides an optical module, including a laser, the laser including a light emitting region and a modulation region, and light emitted by the light emitting region emitting toward the modulation region; a first driver circuit, the first driver circuit being connected to the light emitting region, so that the light emitting region emits light with adjusted optical power; and a second driver circuit, the second driver circuit being connected to the modulation region, so that the modulation region changes the optical power of the light emitted from the light emitting region.

A laser transmitter is provided that includes a seed signal generator, an amplitude modulator and a power amplifier. The seed signal generator is configured to generate a seed signal that has a continuous waveform. The amplitude modulator is configured to generate a flat-top pulse signal based on the seed signal. The power amplifier is configured to generate a laser output signal based on the flat-top pulse signal.