Multiphoton imaging with blue-diode-pumped SESAM-modelocked Ti:sapphire oscillator generating 5 nJ 82 fs pulses

Watt-level tunable Ti:Sapphire laser directly pumped with green laser diodes

We demonstrate a Ti:Sapphire laser generating in excess of 1.2 W in continuous-wave operation when pumped directly with four green laser diodes eliminating the need for a complex pump laser. As a result, improvement of laser efficiency is achieved without sacrificing beam quality. Tunability within the range of 740-840 nm is attained validating the concept of a direct laser-diode pumped Ti:Sapphire laser.

Spectrally combined four-diode-pumped femtosecond Ti:sapphire laser with 16.3 nJ pulse and its application to video-rate coherent anti-Stokes Raman scattering spectro-microscopy

We demonstrate the generation of high-energy femtosecond pulses by a spectrally combined four-diode-pumped Ti:sapphire laser with semi-conductor saturable absorber mirror mode locking. To achieve energy scaling, the laser cavity was extended using a design based on the Herriott multipass cell. The laser operates at a 17.5 MHz repetition rate and generates pulses with energies as high as 16.3 nJ and 80 fs in duration. The signal-to-noise ratio at the fundamental frequency showed an extinction ratio of >50 dB relative to the carrier. This compact single laser was applied to video-rate forward and backward coherent anti-Stokes Raman scattering spectro-microscopy with a pixel dwell time of 122 ns, which is the lowest dwell time ever achieved, to the best of our knowledge.

A Hybrid Self-Seeded Ti:sapphire Laser with a Pumping Scheme Based on Spectral Beam Combination of Continuous Wave Diode and Pulsed DPSS Lasers

A wide variety of applications require high peak laser intensity in conjunction with a narrow spectral linewidth. Typically, injection-locked amplifiers have been employed for this purpose, where a continuous wave oscillator is amplified in a secondary external resonant amplifier cavity using a pulsed pump laser. In contrast, here we demonstrate a setup that combines a CW Ti:sapphire oscillator and pulsed amplifier in a single optical cavity, resulting in a compact system. Dichroic beam combination of blue wavelength semiconductor diodes and the green wavelength of a Nd:YAG laser allowed the simultaneous excitation of the Ti:sapphire crystal by both continuous wave and pulsed pump sources. A linewidth of <2MHz is achieved in continuous wave operation, while the linewidth increases to about 10MHz in the combined CW + pulsed mode with a pulse duration of 73ns. A peak pulse intensity of 0.2kW is achieved, which should enable efficient single-pass second harmonic generation in a nonlinear crystal.

Influence of pump beam shaping and noise on performance of a direct diode-pumped ultrafast Ti:sapphire laser

One of the major factors that limits the widespread use of ultrafast titanium sapphire (Ti:S) lasers in life science is its expensive and complex pump source. Broad area diode laser (BA-DL) based pump sources have high potential to solve this problem, since they are compact, inexpensive and very efficient. However, their non-diffraction limited beam profile makes it challenging to achieve high powers in Kerr-lens mode-locked (KLM) operation of Ti:S lasers. In this work, we show that the ideal way to beam shape two spectrally combined BA-DLs with different beam qualities is to aim for a compromise between matching to the cavity mode diameter and the cavity mode Rayleigh range. We furthermore conclude that the relative intensity noise (RIN) of the BA-DL pumped Ti:S laser, another important parameter for imaging applications, is sufficiently low for a wide range of life science applications. However, for applications that are highly sensitive to noise, new laser diode designs are likely necessary to reduce inherent noise originating within the laser diode.

Characterization of a carrier-envelope-offset-stabilized blue- and green-diode-pumped Ti:sapphire frequency comb

Diode-pumping of Ti:sapphire provides a low-cost route to high-quality frequency-comb sources, exploiting the potential of direct diode modulation for wideband control of the carrier-envelope-offset frequency. We present here an f_REP- and f_CEO-locked, directly diode-pumped Ti:sapphire frequency comb, producing 66-fs pulses at 800 nm and employing f-to-2f interferometry and current modulation of a 462-nm blue laser diode to achieve a stabilization bandwidth extending to ∼70  kHz. Characterizations of the f_REP and f_CEO phase noise are compared to relative intensity noise spectra of the pump diodes to provide insights into how the diode design and performance transfer into the comb stability, suggesting a lower contribution to f_REP and f_CEO noise from the blue laser diode than from the green diode.

Ultrafast diode-pumped Ti:sapphire laser with broad tunability

We report a broadly wavelength-tunable femtosecond diode-pumped Ti:sapphire laser, passively mode-locked using both semiconductor saturable absorber mirror (SESAM) and Kerr-lens mode-locking (KLM) techniques. Using two pump laser diodes (operating at 450 nm), an average output power as high as 433 mW is generated during mode-locking with the SESAM. A tunability range of 37 nm (788-825 nm) was achieved with the shortest pulse duration of 62 fs at 812 nm. In the KLM regime, an average output power as high as 382 mW, pulses as short as 54 fs, and a tunability of 120 nm (755-875 nm) are demonstrated.