LDH Series

• Higher excitation precision

• Faster data acquisition

• Improved signal quality

• More reliable long-term performance

• Consistent output

• Seamless system integration

The PicoQuant LDH Series is a family of picosecond pulsed laser diode heads designed to provide precise and stable optical excitation for time-resolved measurements. The series covers an exceptionally broad spectral range from 375 nm to 1990 nm, allowing researchers to select an excitation wavelength according to the sample, fluorophore, semiconductor material, or measurement technique. Different diode configurations are available to balance pulse duration, repetition rate, optical power, and beam-delivery requirements. Standard LDH models provide short picosecond pulses with repetition rates of up to 40 MHz or 80 MHz, depending on the model. Specialized configurations include higher-power tapered-amplified (TA) versions and longer-pulse P-type versions for applications requiring increased excitation power. A major advantage of the LDH Series is its flexibility in optical delivery. Laser heads can be supplied with free-space output or optional coupling into single-mode, polarization-maintaining single-mode, or multimode fibers. PicoQuant specifies typical coupling efficiencies above 40% for single-mode fiber and above 80% for multimode fiber configurations. For experiments requiring multiple excitation wavelengths, several LDH heads can be integrated using PicoQuant's Laser Combining Unit (LCU). The LCU can combine up to five laser lines into a polarization-maintaining single-mode fiber, making it useful for multi-color fluorescence and time-resolved spectroscopy setups. The LDH Series is fully compatible with PicoQuant's PDL 800-D, Sepia PDL 810, and Sepia PDL 828 drivers, allowing the laser heads to be incorporated into either single-wavelength or multi-wavelength experimental systems.

Product Type: Picosecond Pulsed Laser Diode Head Product Family: LDH Series Manufacturer: PicoQuant Wavelength Range: 375–1990 nm Pulse Width: Typically <40–200 ps* Maximum Repetition Rate: Up to 80 MHz Average Optical Power: Up to 380 mW* CW Optical Power: Up to 100 mW* Output Mode: Free-Space / Optional Fiber-Coupled Fiber Options: SM / PM-SM / MM SM Fiber Coupling Efficiency: >40% typical MM Fiber Coupling Efficiency: >80% typical Numerical Aperture: 0.55 Typical Divergence with Optics: θ∥ ≈ 0.11 mrad / θ⊥ ≈ 0.32 mrad Polarization: Typically Linear PER: >10 dB typical Optional Cooling: Peltier Cooling Peltier Stability: Better than 1 K Power Stability with Cooling: 1% RMS / 3% peak-to-peak over 12 h under specified conditions Compatible Drivers: PDL 800-D / Sepia PDL 810 / Sepia PDL 828 Laser Combining: Up to 5 laser lines with LCU Laser Class: Class 3B

1. Fluorescence Lifetime Imaging Microscopy (FLIM)

• FLIM

• Fluorescence Lifetime Imaging

• Time-Resolved Fluorescence Microscopy

• Biological Imaging

• Cellular Imaging

• Fluorescence Dynamics

Short picosecond excitation pulses provide accurate timing references for measuring fluorescence decay, making the LDH Series highly suitable for time-resolved fluorescence and FLIM. PicoQuant specifically identifies FLIM as one of the key techniques supported by the platform. 2. Fluorescence Correlation Spectroscopy (FCS)

• FCS

• Single-Molecule Fluorescence

• Molecular Dynamics

• Diffusion Measurements

• Biomolecular Interaction Studies

The short, precisely timed excitation pulses can be used together with photon-counting and time-correlated detection systems for fluorescence fluctuation and correlation measurements. 3. Time-Resolved Photoluminescence (TRPL)

• TRPL

• Photoluminescence Lifetime

• Semiconductor Characterization

• 2D Materials

• Perovskite Research

• Solar Cell Characterization

The LDH Series provides suitable pulsed excitation for measuring carrier dynamics and photoluminescence lifetimes in semiconductor and optoelectronic materials. PicoQuant specifically lists TRPL among the time-resolved techniques supported by LDH laser heads. 4. Quantum Optics

• Single-Photon Experiments

• Quantum Light Sources

• Photon Correlation

• Quantum Communication

• Quantum Computing Research

• Photonic Quantum Systems

The short pulse duration and flexible wavelength selection make LDH sources suitable for controlled excitation in quantum-optics experiments, including single-photon and photon-correlation measurements. 5. Time-Correlated Single-Photon Counting

• TCSPC

• Time-Resolved Fluorescence

• Photon Timing

• Single-Photon Detection

• Lifetime Measurements

LDH laser heads can be used as pulsed excitation sources together with PicoQuant TCSPC electronics for high-precision photon timing measurements. 6. LiDAR & Ranging

• LiDAR

• Time-of-Flight Measurement

• Laser Ranging

• Distance Measurement

• Remote Sensing

• Satellite Laser Ranging

PicoQuant identifies LiDAR and ranging among the applications supported by the LDH platform, particularly where precisely controlled pulsed excitation is required. 7. Materials Science

• 2D Materials Research

• Semiconductor Characterization

• Photoluminescence

• Carrier Dynamics

• Exciton Dynamics

• Optical Characterization

The broad wavelength range allows the LDH Series to be matched to different materials and excitation requirements, including research into 2D materials and semiconductor systems.