LDH-FA Series Fibre-Amplified Picosecond Laser Diode Heads

Fibre-amplified picosecond laser diode heads deliver high pulse energies, clean temporal profiles, and tunable repetition rates for advanced scientific applications. 266–1560 nm.

Key Benefits

• Higher excitation power — average output power up to 450 mW depending on wavelength
• Cleaner time-domain measurements — short, clean picosecond pulses with well-defined temporal profiles
• More flexible experiment design — collimated or fibre-coupled output across a wide spectral range
• Reliable performance at high repetition rates — tunable up to 80 MHz
• Stable output for quantitative workflows — power stability under 3% RMS over 12 hours
• Precise timing in synchronised setups — compatible with established PicoQuant PDL drivers

Fibre-Amplified Picosecond Excitation with Broad Spectral Coverage

The LDH-FA Series delivers high-power picosecond excitation across a broad spectral range from deep UV to the near-infrared. These laser heads use a Master Oscillator Fibre Amplifier (MOFA) concept with optional frequency conversion to provide short, clean pulses with variable repetition rates up to 80 MHz. A master oscillator generates infrared picosecond pulses using PicoQuant’s proven gain-switching techniques; the seed laser output is directly connected to a single- or double-stage fibre amplifier, which boosts output by several dB while preserving emission wavelength, polarisation, and pulse width.

The amplified infrared seed enables efficient generation of UV, visible, and infrared outputs while preserving pulse quality and stability, supporting demanding experiments in fluorescence, microscopy, and materials research. Both fibre-coupled and free-space versions are available for flexible integration into a wide variety of scientific setups.

Conversion to UV, Green, Yellow, Orange, or Red

The high pulse energies of the amplified infrared lasers permit efficient wavelength conversion using single-pass second harmonic generation (SHG), third harmonic generation (THG), or fourth harmonic generation (FHG). This makes it possible to generate picosecond pulses at 266, 355, 515, 532, 557, 596, 766, or 774 nm with adjustable repetition rates up to 80 MHz and pulse widths below 100 ps (FWHM).

As an example, the pulse width (FWHM) of an LDH-P-FA-355 emitting at 355 nm was measured at 47.4 ps via streak camera — a measurement credited to Dr. Tobias Korn, working in Prof. Dr. Christian Schüller’s group at the University of Regensburg, Germany.

Average Output Power up to 450 mW

Laser heads are available in two versions: emitting from a polarisation-maintaining single-mode fibre with FC/APC connector, or generating a collimated output beam. Achievable average power depends on the number of amplification stages and the efficiency of the optional frequency conversion stage, reaching more than 450 mW for the highest-power configurations at maximum repetition rate.

Repetition Rates up to 80 MHz

Most LDH-FA Series laser heads operate at repetition rates up to 80 MHz. Minimum repetition rate depends on the specific fibre amplifier architecture used in each head — see the Specifications table below for per-type ranges.

Compatible Laser Drivers

The LDH-FA Series is fully compatible with the Sepia PDL 828, Sepia PDL 810, and PDL 800-D laser drivers. This ensures reliable operation across a wide range of repetition rates, trigger modes, and wavelength configurations, allowing straightforward integration into both single- and multi-wavelength experimental setups.

Optional Fibre Coupling and Laser Combining

LDH-FA heads can be ordered with fibre-coupled output for single-mode, polarisation-maintaining single-mode, or multi-mode fibres (with the exception of wavelengths below 355 nm). FC/APC connectors are recommended for most applications, as they minimise back reflections that can interfere with laser stability. Coupling efficiencies typically reach above 60% for single-mode and above 80% for multi-mode, with each unit aligned prior to delivery for a stable, well-defined beam at the fibre output.

LDH-FA heads can also be combined with other laser heads from the LDH Series into a single delivery fibre using PicoQuant’s Laser Combining Unit (LCU).

Suitable for All Major Scientific Disciplines

The LDH-FA Series provides the spectral range, pulse quality, and power levels required across a wide spectrum of scientific disciplines. Its tunable picosecond excitation supports studies in life and materials science, as well as emerging fields such as quantum technologies and advanced optical sensing including LiDAR. By combining flexible wavelengths with high pulse energies and stable timing performance, these laser heads offer a reliable foundation for experiments that demand precise control of excitation conditions.