The bh BDS-SM series picosecond diode lasers feature a timing stability in the sub-4ps range. The figure below shows a series of TCSPC recordings of the laser pulses over a period of 640 seconds after power-on of the laser. The left panel shows the data displayed in colour-intensity mode, the right panel in multi-curve mode. The example shown right is that timing drift, if present at all, is far smaller than the laser pulse width of 49 ps FWHM. That means TRS, FLIM, or NIRS experiments can be started from the first second after turning on the laser, and do not require repeated reference measurements.
All BDS-SM lasers are tansversal single-mode lasers. That means, the emission virtually comes from a single spot inside the laser, as such the laser beam can be focused in a diffraction-limited spot or coupled into a single-mode fibre. The BDS-SM lasers are available with free-beam output, with fixed (pig tail) fibres, with Lasos Precision fibre connectors, and with Point-Source-Type couplers.
Due to an internal power regulation loop, the BDS-SM lasers feature extraodinarily stable optical power. Intensity drift by temperature changes and intensity noise by mode fluctuations in the laser diode are almost entirely suppressed. The lasers have a fast on/off function which can be used for beam blanking in scanning applications and for laser multiplexing.
The BDS-SM lasers deliver a trigger output signal for synchronisation to bh TCSPC devices. The output amplitude is sufficient for distribution of the trigger signal to several TCSPC modules. The timing stability of the trigger pulses versus the optical pulses is better than 5 ps. Extended warm-up times are not needed. After switch-on of the power supply, the timing is stable within about 4 picoseconds.
The BDS-SM lasers can be triggered externally. To keep the internal power regulation loop in the active range the trigger frequency should be in the range from 10 to 80 MHz. The laser switches between the external trigger signal and the internal 20-50-80 MHz clock by sensing the average voltage at the synchronisation input. If the average voltage is above 2.5 V the laser uses the internal clock, if it is below 2.5 V it synchronises to the external signal.
Key Spec
- Single-Transversal Mode Picosecond and CW Diode Laser
- Pulse Width Down to 30 ps
- Excellent Timing Stability – No Warm-Up Time Necessary
- Optical Power up to 5 mW in Pulsed Mode
- Optical Power up to 50 mW in CW Mode
- Free Beam or Single-Mode Fiber Output
- Repetition Rate 20 MHz /50 MHz / 80 MHz / CW (Switchable)
- Trigger Input for Synchronisation to External Clock Sources
- Internal Power Stabilization Loop
- Fast ON / OFF / Multiplexing Capability
- All Electronics Integrated in 40 x 40 x 120 mm Case
- No External Driver Unit Required
- Simple +12 V Supply
- 40 x 40 x 120 mm3 or 40 x 70 x 120 mm3
Fluorescence lifetime
FLIM
Phosphorescence lifetime
FLIM-FRET
