UVL-FB Series Pulsed LED Light Sources

Picosecond Ultraviolet Light Source

  • Picosecond Pulsed LED
  • Small Size OEM Module, 40 mm x 40 mm x 120 mm
  • Pulse Width 500 ps to 800 ps
  • Pulse Repetition Rate 20 MHz, 50 MHz, 80 MHz
  • Wavelengths: 270 nm and 310 nm
  • Free Beam Output
  • Power Approx. 50 µW at 50 MHz
  • Fast ON / OFF / Multiplexing Capability
  • All Electronics Integrated
  • Simple +12 V Power Supply
  • Compatible with all bh TCSPC Devices


The UVL series light sources are based on ultraviolet LEDs which are driven by high-speed picosecond pulse electronics. The devices provide pulsed light in a spectral range where diode lasers are not available. Pulse repetition rate is 20, 50, and 80 MHz, pulse width is in the range form 500 ps to 800 ps. Compared with lasers, the optical power is relatively modest. Another difference to lasers is that the emission does not come from a single spot but from a relatively large area. It therefore cannot be focused into a diffraction-limited spot or injected into optical fibres. Nevertheless, in combination with the high sensitivity of TCSPC the UVL-FB can be used for a wide range of fluorescence decay experiments in the ultraviolet spectral range. The figure below shows a fluorescence decay curve of Tryptophane, excited by a UVL-FB-270nm light source. The detector was a HPM-100-06 hybrid detector, the TCSPC module an SPC-150NX.

When the UVL-FB is integrated in complex fluorescence measurement systems it can be used as it is. All that is needed is a +12 V power supply and a voltage divider to set the power-control input voltage.

For laboratory application it is recommended that the UVL-FB is used with a LSB-C control box, which has controls for the repetition rate and output power.





Wavelength / nm

270, 310

Repetition Rate / MHz

20, 50, 80

Pulse Width (FWHM, at Medium Power, at Maximum Power) 2)

typ. 580 ps, typ. 700 ps

Optical Power

Approximately 50 µW

Power Control Range

10 % to 100 %

Optical Beam Dimensions

see Figure in Datasheet

Trigger Output, to TCSPC Modules

Pulse Amplitude

-1.5 V (Peak) into 50 Ω

Pulse Width

1 ns

Output Impedance

50 Ω



Jitter between Trigger and Optical Pulse

< 10 ps

Synchronisation Input

Input Amplitude

+3.3 V to +5 V into 50 Ω

Duty Cycle

10 to 30 %; DC Equivalent must be < 2.5 V

Input Frequency

20 to 80 MHz

Switch between Internal Clock and Sync Input

Automatic, by Average Voltage at Trigger Connector

Control Inputs

Emission ON / OFF

TTL / CMOS, low means OFF, Internal Pull-Up

Response of Optical Output to Emission ON / OFF Signal

< 1 µs

External Power Control

Analog Input, 0 to +10 V

Response Time of Optical Output to Power Control

< 4 µs for Power 10 to 100 %

Frequency 80 MHz

Active H, internal Pull-Down Resistor

Frequency 50 MHz

Active H, internal Pull-Up Resistor

Frequency 20 MHz

Active H, internal Pull-Down Resistor

Device Runs at 50 MHz When Frequency Inputs Unconnected

Power Supply

Power Supply Voltage

+9 V to +15 V

Power Supply Current at 12 V

300 mA to 400 mA

Mechanical Data

Dimensions (width x height x depth)

(40 x 40 x 120) mm

Mounting Thread

four M3 Holes

Heat Sink Requirements

< 2 °C / W 1)

Maximum Values

Power Supply Voltage

0 V to +15 V

Voltage at 'Laser ON/OFF' and 'Frequency' Inputs

-2 V to +7 V

Voltage at 'Laser Power' Input

-12 V to +12 V

Ambient Temperature

0 °C to +40 °C

(1) OEM version without active cooling must be mounted on heat sink. Case temperature must remain below 40 °C.



The bh TCSPC Handbook
10th edition, September 2023


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