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We report on the self-stabilized dissipative-soliton laser with an energy scalability by using a semi-conductor saturable absorber mirror (SESAM) as the pulse stabilizer for the first time. By tailoring the fluence on the SESAM relying on the two-photon absorption effect so that its reflectivity has a negative slope with respect to the fluence, the intra-cavity pulse dynamics is self-stabilized to produce single pulses only, resulting in a 48-nJ pulse energy and an unprecedented pump-to-output power conversion efficiency of 63%. Therefore, it resolves a long standing problem of the formation of multiple pulses in high-energy mode-locked lasers and thus opens a way to build high repetition-rate oscillators with ≥ microjoules pulse energies without any external amplifiers.

We report absolute frequency measurement of the $6s6p{\phantom{\rule{0.16em}{0ex}}}^{1}{P}_{1}--6s7s{\phantom{\rule{0.16em}{0ex}}}^{1}{S}_{0}$ transition at 1077.3 nm of $^{174}\mathrm{Yb}$ in a hollow-cathode lamp (HCL). The frequency of coupling laser was stabilized to the $6{s}^{2}{\phantom{\rule{0.16em}{0ex}}}^{1}{S}_{0}--6s6p{\phantom{\rule{0.16em}{0ex}}}^{1}{P}_{1}$ transition at 398.9 nm using an Yb atomic beam, and the coupling laser beam was then overlapped with the counterpropagating probe laser beam at 1077.3 nm in the Yb HCL to obtain a Doppler-free signal of laser-induced birefringence for the frequency stabilization of the probe laser. Systematic frequency shifts of both transitions as a function of the discharge current of the Yb HCL were analyzed using an Yb-doped fiber laser frequency comb. The absolute frequency of the $6s6p{\phantom{\rule{0.16em}{0ex}}}^{1}{P}_{1}--6s7s{\phantom{\rule{0.16em}{0ex}}}^{1}{S}_{0}$ transition was measured to be 278 281 521.4(7.2) MHz, and from the published frequency of the transition, the absolute frequency of the $6{s}^{2}{\phantom{\rule{0.16em}{0ex}}}^{1}{S}_{0}--6s7s{\phantom{\rule{0.16em}{0ex}}}^{1}{S}_{0}$ two-photon transition at 291.1 nm was determined to be 1 029 807 509.2(7.2) MHz with the relative standard uncertainty of $7.0\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}9}$.

We present an ultrabroadband supercontinuum (SC) frequency comb generation covering the optical spectrum more than 1.2 octave from 570 nm to 1350 nm with a near flat-top power spectrum by using a mode-locked Yb fiber laser at 1030 nm as a master oscillator (MO). The repetition rate of the MO that has a spectral-width of 28 nm is 152 MHz and is phase-locked to a reference frequency synthesizer. A power amplifier is used to boost up the output power up to 1.3 W and the positively chirped amplified pulses are compressed by using a transmission grating pair. We used a commercially-available 10-cm long photonic crystal fiber that has two zero-dispersion wavelengths at 800 nm and 1093 nm, respectively, to generate an ultrabroadband SC frequency comb. Optical spectrum depending on the frequency chirp and pulse-width of the amplified pulses are analyzed to find an optimum coupling power as well as an optimum chirp parameter. We found that a dimensionless chirp parameter of 8.6 and a pulse-width of 517 fs for a chirped Gaussian pulse resulted in the optimum spectrum width of 1.2 octave.

We report on the experimental observations of a period-doubling route to chaos and a total mode-locking between two lowest-order lateral modes of a GaAs ridge wave-guide diode laser at 795 nm. A self-starting passively mode-locking was achieved in an extended-cavity diode laser (ECDL) operating in a gain saturation regime. In the period-doubling mode-locked state, the RF spectra associated with the coherently coupled lateral TE(0) and TE(1) modes, consisted of harmonics (nf(rep)/2, n is an integer) of the half of pulse repetition rate f(rep)/2 and the period (2T) of the pulse train was two-times longer than the pulse round-trip time T. On the other hand, in the total mode-locked state, the RF spectra and the pulse train corresponding to the TE(0) and TE(1) modes had exactly the same features compared to those of the period-doubling mode-locked state, except the RF spectra and the pulse train of the TE(1) mode were shifted by f(ref)/4 in frequency and by T in time, respectively, indicating the pulses actually traveled alternatively through two lateral modes. The total mode-locking and also chaotic pulsations were observed at slightly different operation parameters, e.g. at different feedback angle of the grating, which was used as an output coupler of the ECDL.

We present a single-polarization Yb-doped fiber laser mode-locked in a regime of SESAM two-photon absorption. The laser emits ultra-stable pulses at 1030 nm with a pulse-width of 2 ps, an pulse-energy of 1 nJ at the repetition rate of 186 MHz, a spectral-width of 26 nm, and the dechirped pulse-width of 116 fs, respectively.

A self-starting passively modelocked extended-cavity diode laser (ECDL) in the Littrow configuration is demonstrated for the first time by using a near-infrared ridge-waveguide GaAs diode laser at the gain saturation regime.

We present a high repetition-rate all-normal-dispersion Yb fiber laser operating in two-photon absorption regime of a SESAM. Ultra-stable pulses with 1 nJ energy, compressed pulse-width of 115.9 fs, and spectral-width of 26 nm are generated.

We present a compact coupled optoelectronic oscillator consisting of an actively mode-locked external cavity diode laser and microwave feed-back loop, generaing an optical frequency comb with a stabilized repetition rate of 2.298 GHz at 852 nm.