Experimental investigation of the 2.1-μm single-mode Tm-Ho:KYF laser

We report on the development and comprehensive characterization of a room-temperature single-mode 2-m Tm-Ho:KYF laser. A maximum CW output power of 70 mW at the central wavelength of 2.078 m has been obtained. Using a 5-mm long intracavity birefringent filter the single-mode emission wavelength can be tuned over a range of 40 nm. Both frequency and relative intensity noise have been investigated showing a 1-ms emission linewidth of 600 kHz and an intensity noise spectrum that is quantum-noise limited for Fourier frequencies higher than 1 MHz. PACS 42.55Xi; 42.55Rz; 42.60Pk; 42.70Hj; 42.60Lh     

Widely tunable continuous-wave diode-pumped 2-microm Tm-Ho:KYF4 laser

Continuous-wave laser action at approximately 2 microm is demonstrated in a Tm-Ho:KYF4 single crystal at room temperature. Crystal growth, spectroscopic measurements, and laser results are presented. An output power in excess of 250 mW is obtained with a tuning range of 99 nm, the largest ever published, to our knowledge, for Tm-Ho in any crystalline host.     

Diode-pumped bulk erbium-ytterbium lasers

A comprehensive review of the work done by our group, during the last few years, on diode-pumped cw operating bulk Er : Yb phosphate glass is presented. The high performance of this laser in terms of output power, laser slope efficiency, single longitudinal and transverse mode operation, laser tunability and frequency stability, amplitude noise, and active mode-locking operation, are considered. The combination of this high performance and potential low cost makes these laser devices attractive for a variety of applications including spectroscopy, metrology, optical radars, optical communications, and all optical switching.Prof. F. P. Schäfer on the occasion of his 65th birthday     

Noise characteristics of a high-power ytterbium-doped fibre amplifier at 1083 nm

Experimental results are reported for the noise characteristics of an Yb-doped fibre amplifier pumped at 975 nm, used as a booster of a low-noise narrow-linewidth single-frequency 1083-nm wavelength laser diode. The maximum output power of the amplifier is 1.2 W with a gain larger than 30 dB. An increase of the intensity-noise spectral density relative to the signal, by approximately 6.5 dB, is introduced by the amplification process, due to signal-amplified spontaneous-emission (ASE) beat noise. A remarkable increase of the noise level with decreasing frequency is observed below ≈35 kHz, probably due to technical noise of the amplifier pump diodes. The spectral broadening due to amplifier phase noise was measured to be less than 300 Hz with a 5-kHz-linewidth Nd:YAG laser and that for the 300-kHz-linewidth diode laser at 1083 nm is therefore expected to be in the same range. Received: 5 October 1999 / Revised version: 2 December 1999 / Published online: 24 March 2000     

5-GHz repetition-rate dual-wavelength pulse-train generation from an intracavity frequency-modulated Er-Yb:glass laser

We report the experimental demonstration of nearly transform-limited dual-wavelength pulse trains at a 5-GHz repetition rate that were generated by spectral filtering of an intracavity 2.5-GHz frequency-modulated Er-Yb bulk-glass laser operating at the 1533-nm wavelength. Highly stable dual-wavelength pulse trains with ~165-GHz frequency separation, ~48-ps pulse duration, and ~1-mW average single-mode fiber-coupled power were obtained.     

Er:Yb-doped waveguide laser fabricated by femtosecond laser pulses

Laser action is demonstrated in a 20-mm-long waveguide fabricated on an Er:Yb-doped phosphate glass by femtosecond laser pulses. An output power of 1.7 mW with approximately 300 mW of pump power coupled into the waveguide is obtained at 1533.5 nm. Waveguides are manufactured with the 520-nm radiation from a frequency-doubled, diode-pumped, cavity-dumped Yb:glass laser operating at a 166-KHz repetition rate, with a 300-fs pulse duration.     

Femtosecond micromachining of symmetric waveguides at 1.5 microm by astigmatic beam focusing

We report on a new spatial beam-shaping approach for fabrication of waveguides with a circular transverse profile by femtosecond laser pulses, using an astigmatic beam and controlling both beam waist and focal position in the tangential and sagittal planes. We apply this technique to write single-mode active waveguides at 1.5microm in Er:Yb-doped glass substrates. The experimental results are well described by a simple nonlinear absorption model.     

Gain-saturated two-pump fiber optical parametric amplifiers in the presence of dispersion fluctuation and fourth-order dispersion coefficient

Optical Review - The saturated gain performance of the two-pump fiber optical parametric amplifier (2-P FOPA) in the presence of random dispersion fluctuation as well as fourth-order dispersion...     

5-GHz repetition-rate dual-wavelength pulse-train generation from an intracavity frequency-modulated Er-Yb:glass laser: errata

In our recent Letter,(1) the affiliation of the authors was incorrect and should read as shown above. On p. 1549, in line 19 of the left-hand column the word "pulse" should be replaced with "trace." Finally, in Ref. 11 the name of the first author was misspelled. The correct reference should read as follows: