The HARPIA comprehensive spectroscopy system performs a variety of sophisticated time-resolved spectroscopic measurements in a compact footprint. It offers an intuitive user experience and easy day-to-day maintenance meeting the needs of today’s scientific applications. Extension modules and customization options tailor the HARPIA system to specific measurement needs.

The system is built around the HARPIA-TA transient absorption spectrometer and can be expanded using time-correlated single-photon counting and fluorescence upconversion (HARPIA-TF), third beam delivery (HARPIA-TB), and microscopy (HARPIA-MM) modules. HARPIA is designed for easy switching between measurement modes and comes with dedicated data acquisition and analysis software. Each module is contained in a monolithic aluminum body ensuring excellent optical stability and minimal optical path lengths. For a single-supplier solution, the HARPIA spectroscopy system can be combined with a PHAROS or a CARBIDE laser together with ORPHEUS series OPAs. HARPIA also supports Ti:Sapphire lasers with TOPAS series OPAs.

Video presentation

Pump-Probe

Model	HARPIA
Probe excitation wavelength	1030 nm	515 nm	800 nm
Probe spectral range	460 – 1600 nm	350 – 750 nm	330 – 1400 nm
Spectral range of multichannel detectors	200 – 1100 nm, 900 – 1700 nm, or 900 – 2600 nm
Spectral range of single-channel detectors	180 nm – 24 μm
Delay range	2 ns, 4 ns, or 8 ns
Delay resolution	2.1 fs, 4.2 fs, or 8.3 fs
Laser repetition rate	1 – 1000 kHz
Temporal resolution	< 1.4× pump or probe pulse duration, whichever is longer
Maximum data acquisition rate	4000 spectra/s
SNR ¹⁾	250 : 1

Estimated as the standard deviation of a set of 2500 spectra measured in SCHOTT OG530 glass with 54 nJ, 370 nm pump and > 4.5 mOD at a maximum of the spectrum. Not applicable to all samples and configurations.

Upconversion Mode

Model	HARPIA
Spectral range ¹⁾	300 – 1600 nm
Spectral resolution ²⁾	≈ 100 cm^-1
Delay range	2 ns, 4 ns, or 8 ns
Delay resolution	2.1 fs, 4.2 fs, or 8.3 fs
Temporal resolution	< 1.4× pump or gate pulse duration, whichever is longer
SNR ³⁾	65 : 1

Depending on the gating source, full range covered with different nonlinear crystals.
Limited by the spectral bandwidth of the gating pulse.
Estimated as the standard deviation of a set of 100 points at 50 ps intervals measured in Rhodamine 6G dye at an upconverted wavelength of 360 nm using a PHAROS laser running at 150 kHz repetition rate; assuming 0.5 s averaging per point. Not applicable to all samples and configurations.

TCSPC Mode

Model	HARPIA
Spectral range	320 – 820 nm
TCSPC detector ¹⁾	Standard	High-speed
Temporal resolution	< 180 ps	< 50 ps
Maximum measurement range ²⁾	5 μs
SNR ³⁾	100 : 1

Different models available; contact sales@lightcon.com for details.
Maximum measurement range can be extended with a phosphorescence upgrade.
Estimated by fitting a kinetic trace measured in Rhodamine 6G solution at 580 nm with multiple exponents, subtracting the fit from the data and taking the ratio between the standard deviation of the residuals and the 0.5× maximum signal value, at 250 kHz repetition rate; assuming 5 s averaging per trace. Not applicable to all samples and configurations.

Flash Photolysis Extension

Model	HARPIA
Delay resolution	100 ps
Temporal resolution	2 ns
SNR ¹⁾	40 : 1

Estimated as the standard deviation of a set of 2000 spectra measured in SCHOTT OG530 glass with 515 nm pump and > 10 mOD at a maximum of the spectrum. Not applicable to all samples and configurations.

Third Beam Delivery Module

Model	HARPIA
Delay range ¹⁾	2 ns, 4 ns
Delay resolution	2.1 fs, 4.2 fs

8 ns delay range is available on request; contact sales@lightcon.com for details.

Microscopy Module

Model	HARPIA
Spatial resolution	monochromatic	polychromatic
Spatial resolution	5 µm	10 µm
Spectral range	460 – 1100 nm
Temporal resolution	500 fs
Maximum working distance ¹⁾	13 mm
Sample motion range	13 × 13 × 13 mm

Depends on the objective used; contact sales@lightcon.com for details.

Dimensions

Model	HARPIA
Physical dimensions (L × W × H)	1401 × 621 × 183 mm ¹⁾
Sample chamber area (L × W)	205 × 215 mm

Without external spectrograph.

HARPIA-TA – Ultrafast Transient Absorption Spectrometer

The HARPIA-TA ultrafast transient absorption spectrometer features market-leading characteristics such as 0.05 mOD (10⁻⁴ ΔT/T) sensitivity and the ability to work at high repetition rates up to 1 MHz, when used with a PHAROS or CARBIDE laser and an ORPHEUS series OPA. A high repetition rate allows measuring transient absorption dynamics with excitation pulse energies down to several nanojoules.

HARPIA-TA ultrafast transient absorption spectrometer

HARPIA-TA with internal cryostat mounting option

HARPIA optical layout for pump-probe experiments

HARPIA-TF – Femtosecond Fluorescence Upconversion and TCSPC Module

The HARPIA-TF is a time-resolved fluorescence measurement module that combines fluorescence upconversion and TCSPC techniques. In fluorescence upconversion, the signal from the sample is mixed in a nonlinear crystal with a gating femtosecond pulse to achieve high temporal resolution, which is limited by the duration of the gate and pump pulses.

HARPIA optical layout for fluorescence upconversion measurements

Principle of time-correlated single-photon counting (TCSPC)

Principle of time-resolved fluorescence upconversion

HARPIA-TB – Third Beam Delivery Module

The HARPIA-TB is a third beam delivery module for the HARPIA-TA unit that adds an additional dimension to time-resolved absorption measurements. It allows multi-pulse time-resolved spectroscopic techniques, in which the ongoing pump-probe photodynamics are perturbed by a delayed third pulse. In conjunction with a narrow-bandwidth picosecond pulse source, HARPIA-TB can be used to perform femtosecond stimulated Raman scattering (FSRS) measurements.

HARPIA optical layout for multi-pulse experiments

State transitions and pulse timing in multi-pulse time-resolved transient absorption spectroscopy

Illustration of state transitions and pulse timing in multi-pulse transient absorption spectroscopy

Illustration of Femtosecond stimulated Raman scattering (FSRS)

HARPIA-MM – Microscopy Module

HARPIA-MM is a microscopy module add-on to the HARPIA-TA spectrometer, which enables spatially-resolved pump-probe measurements with a spatial resolution down to 5 μm. The sample can be positioned and scanned in a 13 mm range along XYZ axes using a motorized stage. Microscopic transient transmission and reflection signals can be measured using a broadband or a monochromatic probe.

Modules for bulk and microscopic pump-probe modes

HARPIA-TA with bulk module installed

HARPIA-TA with microscopy module installed

Optical Layouts

HARPIA optical layout for pump-probe experiments

HARPIA optical layout for fluorescence upconversion measurements

HARPIA optical layout for multi-pulse experiments

Drawings

Comprehensive Spectroscopy System HARPIA

Drawing of HARPIA system with HARPIA-TB and HARPIA-TF modules

Principle of time-resolved fluorescence upconversion

Principle of time-correlated single-photon counting (TCSPC)

Illustration of state transitions and pulse timing in multi-pulse transient absorption spectroscopy

Illustration of Femtosecond stimulated Raman scattering (FSRS)

HARPIA Service App – System Control and Data Acquisition Software

A single software solution for all measurement modes, featuring:

Wizard-guided measurements and calibration
Measurement presets
Measurement noise suppression using data balancing and outlier detection
Diagnostics and data export tools
REST API for remote experiment control using third-party software

CarpetView – Data Analysis Software

An ultrafast spectroscopy data analysis software, featuring:

Publication-quality figure preparation and data export tools
Advanced data wrangling: slicing, merging, cropping, shifting, smoothing, fitting, subtracting, etc.
Probe spectral chirp correction, calibration and deconvolution
Advanced global and target analysis
Support for three-dimensional data sets (2D electronic spectroscopy, fluorescence lifetime imaging)

Screenshots

HARPIA Service App main window

CarpetView main window

Global analysis windows of CarpetView

Target analysis windows of CarpetView

HARPIA measurement samples

Spectral dynamics of beta-carotene in solution acquired using HARPIA-TA. Measurement conditions: 100 kHz repetition rate, 490 nm pump wavelength, < 10 nJ pump pulse energy, 13 s/spectrum acquisition time.

Fluorescence dynamics of DCM laser dye in solution acquired using HARPIA-TF in fluorescence upconversion mode. Measurement conditions: 100 kHz repetition rate, 430 nm pump wavelength.

Fluorescence dynamics of DCM laser dye in solution acquired using HARPIA-TF in TCPSC mode. Measurement conditions: 100 kHz repetition rate, 430 nm pump wavelength.

Single perovskite crystallite pump-probe spectral kinetics, pump at 400 nm. Pump-probe spot marked by the small circle

Single perovskite crystallite pump-probe kinetics. Pump-probe spot marked by the small circle. Measurement conditions: 400 nm pump wavelength, 200 kHz repetition rate, 2 nJ pump pulse energy, 0.5 s/spectrum acquisition time, and Plan Fluor 4x/0.13 objective.

Pump-probe dynamics of GaAs wafer in IR measured using signal and reference single-channel detectors. Measurement conditions: 75 kHz repetition rate, 700 nm pump wavelength, 1 s/point acquisition time.

Pump-dump-probe dynamics of DCM laser dye with dump pulse resonant to the emission band of DCM. Measurement conditions: 50 kHz repetition rate, 515 nm pump wavelength, 700 nm dump wavelength, 21 ps dump delay, 90 nJ pump pulse energy, 190 nJ dump pulse energy.

Nanosecond spectral dynamics of meso‑Tetraphenylporphine in solution acquired using HARPIA in flash photolysis mode. Measurement conditions: 1.8 kHz repetition rate, 343 nm pump wavelength, 5.4 μJ pump energy.

Femtosecond stimulated Raman scattering dynamics of neoxanthin

FSRS dynamics of neoxanthin using Harpia-TA with Harpia-TB module. Measurement conditions: 25 kHz repetition rate, 440 nm actinic pump wavelength, 200 nJ pulse energy, 530 nm Raman pump wavelength, 300 nJ pulse energy.

HARPIA performance at high repetition rate

The HARPIA spectroscopy system achieves an excellent signal‑to‑noise ratio at high repetition rate and low energy excitation conditions. The graphs below compare the SNR of difference absorption spectra obtained with a Ti:Sapphire laser running at 1 kHz and a PHAROS laser running at 64 kHz with the same acquisition time.