High Power Picosecond Laser
- Any wavelength between 765 and 780 nm, 1064 nm, 1532 nm
- Pulse width typically 70 ps (FWHM) or 0.5 ns (FWHM)
- Option to tune pulse duration from 0.15 to 0.5 ns for high powered versions
- Average output power between > 400 mW and > 1.5 W (depending on wavelength)
- Repetition rates from single shot up to 80 MHz, external or internal triggering
- Collimated output
The VisIR is a versatile and flexible high power picosecond laser platform based on a Master Oscillator Fibre Amplifier (MOFA) concept with frequency conversion. The master oscillator generates infrared picosecond pulses at 1064 nm or 1530 nm with variable repetition rates up to 80 MHz using the proven gain-switching techniques from PicoQuant. The output of this seed laser is directly connected to a multi-stage fibre amplifier, which boosts the output from the seed laser by several dB while maintaining the other characteristics of the seed laser beam like the emission wavelength, polarisation and the pulse width.
Average output power > 1.5 W
The high pulse energies of the amplified 1530 nm infrared laser permit an efficient wavelength conversion using single pass second harmonic generation (SHG). In that way it is possible to generate picosecond pulses at 766 nm with an average output power of more than 1.5 W (VisIR-765-HP „STED“). The VisIR can be operated at 12 different internally selectable repetition rates between 31.25 kHz and 80 MHz and can also be triggered externally by TTL or NIM signals at any repetition rate between single shot and 80 MHz. This feature is extremely useful for a perfect synchronisation of excitation and depletion laser in a stimulated emission depletion (STED) set-up.
Flexible pulse duration
The high power picosecond laser can be configured to generate either short pulses of 70 ps or extended pulses of 0.5 ns (FWHM). The extended pulse duration of 0.5 ns is ideal for e.g., STED microscopy as longer pulses or even continuous-wave excitation can expose the sample to an unnecessary amount of radiation, leading to increased photobleaching. By combining the VisIR with our programmable pulse generator PPG 512, the pulse duration can be configured to any length from 0.15 to 0.5 ns. This permits fine control of not only the pulse parameter but also the coherence length of the laser. This is of great help for diffusion measurements in medical application.
PicoQuant has also developed an upgrade for optical pulse width adjustment using both a PPG 512 and an integrated EOM. This upgrade allows for pulse width adjustment from < 180 up to 500 ps with improved coherence length and spectral width close to the transform limit.
Excellent beam quality
The VisIR features a nearly perfectly circular and gaussian shaped beam profile (TEM00) which can be specified as a value of M² < 1.1, with a typical figure of about M² ~ 1.02. That is an important parameter for further accurate beam shaping (e.g. “STED-Donut” for the VisIR-765-HP “STED”).
Compact stand alone device
The VisIR high power picosecond laser is a stand alone device with a special design optimised for maximum heat dissipation. It includes all driving functions of the established PDL series laser driver such as choice of repetition rate and trigger source. An optional remote control for the VisIR allows to set the trigger source, the repetition rate, and the general output power of the laser.
Fibre coupling
The VisIR can be optionally coupled into a variety of optical fibres (multi-mode, single mode, or polarisation maintaining single mode) via different connector types. We recommend FC/APC connectors for most applications, since they prevent back reflections that can interfere with laser stability.