RESUMO
We present amplitude noise characterization of a low-cost continuum source tunable from 800 to 1250 nm, with the pulse duration of 30 fs, and average output power up to 140 mW at 80 MHz pulse repetition rate. The system is based on a SESAM-modelocked, solid-state Yb tungstate laser plus spectral broadening via a microstructured fiber followed by pulse compression with a simple prism compressor. The measured RMS amplitude noise of 1.2 to 2.5% in the whole tunable range is comparable to the modelocked oscillators. Additionally, we show an excellent agreement between simulated and the experimentally measured spectra.
RESUMO
We developed a low-cost, low-noise, tunable, high-peak-power, ultrafast laser system based on a SESAM-modelocked, solid-state Yb tungstate laser plus spectral broadening via a microstructured fiber followed by pulse compression. The spectral selection, tuning, and pulse compression are performed with a simple prism compressor. The output pulses are tunable from 800 to 1250 nm, with the pulse duration down to 25 fs, and average output power up to 150 mW, at 80 MHz pulse repetition rate. We introduce the figure of merit (FOM) for the two-photon and multi-photon imaging (or other nonlinear processes), which is a useful guideline in discussions and for designing the lasers for an improved microscopy signal. Using a 40 MHz pulse repetition rate laser system, with twice lower FOM, we obtained high signal-to-noise ratio two-photon fluorescence images with or without averaging, of mouse intestine section and zebra fish embryo. The obtained images demonstrate that the developed system is capable of nonlinear (TPE, SHG) imaging in a multimodal operation. The system could be potentially used in a variety of other techniques including, THG, CARS and applications such as nanosurgery.
RESUMO
We present a portable ultrafast Semiconductor Disk Laser (SDL) (or vertical extended cavity surface emitting laser-VECSELs), to be used for nonlinear microscopy. The SDL is modelocked using a quantum-dot semiconductor saturable absorber mirror (SESAM), delivering an average output power of 287 mW, with 1.5 ps pulses at 500 MHz and a central wavelength of 965 nm. Specifically, despite the fact of having long pulses and high repetition rates, we demonstrate the potential of this laser for Two-Photon Excited Fluorescence (TPEF) imaging of in vivo Caenorhabditis elegans (C. elegans) expressing Green Fluorescent Protein (GFP) in a set of neuronal processes and cell bodies. Efficient TPEF imaging is achieved due to the fact that this wavelength matches the peak of the two-photon action cross section of this widely used fluorescent marker. The SDL extended versatility is shown by presenting Second Harmonic Generation images of pharynx, uterus, body wall muscles and its potential to be used to excite other different commercial dyes. Importantly this non-expensive, turn-key, compact laser system could be used as a platform to develop portable nonlinear bio-imaging devices.
RESUMO
We demonstrate a compact diode-pumped fundamentally modelocked Er:Yb:glass laser with a record high repetition rate of 101 GHz, generating 35 mW average power in 1.6-ps pulses in the 1.5-microm telecom window. This performance makes the laser an attractive pulse generator to be used in advanced high-speed return-to-zero (RZ) telecom systems.
RESUMO
We present a multiwavelength source with a spectral width of 42 nm at -20 dB. The frequency comb is generated by spectrally broadening the output of an amplified 50 GHz Er:Yb:glass laser with a highly nonlinear photonic crystal fiber. After spectral flattening the comb covers 37 channels with 5.4 mW average power per channel, and locking only one central wavelength channel to the International Telecommunication Union grid results in a maximum frequency error of 0.24% for all channels.
