CRONUS-2P is a femtosecond laser providing watt-level three synchronized outputs with high repetition rate, short pulse duration, and GDD control, making it the ultimate source for nonlinear microscopy. In standard configuration, the two independently tunable outputs, operating separately or simultaneously, cover 680 – 960 nm and 960 – 1300 nm, respectively, while the third is fixed at 1025 nm and is accessible in parallel. Thus, the CRONUS-2P can be used for simultaneous excitation of multiple fluorescent probes, calcium indicators, or opsins at their absorption maxima, whereas second- and third‑harmonic emission (SHG and THG) can be spectrally shifted for ease of detection or resonant enhancement.

The two tunable and simultaneous channels also enable advanced coherent anti-Stokes and stimulated Raman scattering (CARS and SRS) applications with dual-band imaging, a broader selection of vibrational resonance frequencies, constant-difference dual‑beam tuning, resonant enhancement, and more.

CRONUS-2P configurations:

Standard: 680 – 960 nm (tunable), 960 – 1300 nm (tunable), and 1025 nm (fixed)
Dual output A: 680 – 960 nm (tunable), 680 – 960 nm (tunable), and 1025 nm (fixed)
Dual output B: 960 – 1300 nm (tunable), 960 – 1300 nm (tunable), and 1025 nm (fixed)

Output Characteristics

	Output A	Output B	Output C
Tuning range ¹⁾	680 – 960 nm	960 – 1300 nm	1025 nm (fixed)
Output power ²⁾	> 3 W @ 920 nm	> 2.5 W @ 1100 nm	> 2.5 W
Pulse duration ^{3) 4)}	< 160 fs
Repetition rate	77 ± 1 MHz
Beam quality, M² ³⁾	< 1.2
Polarization	Linear, horizontal
Beam divergence, full angle	< 1 mrad		< 1.5 mrad
Beam diameter ³⁾ (1/e²)	3.0 ± 0.4 mm	3.2 ± 0.4 mm	2.8 ± 0.4 mm
Beam ellipticity ³⁾	> 0.8
Beam astigmatism ³⁾	< 20%
Beam pointing stability ⁵⁾	< 200 µrad		n/a
Long-term power stability ^{3) 6)}	< 1%
GDD control range	−10000 to −35000 fs² @ 700 nm −3000 to −20 000 fs² @ 800 nm 0 to −10 000 fs² @ 960 nm	0 to −10 000 fs² @ 960 nm −3000 to −10 000 fs² @ 1100 nm −6 000 to −12 000 fs² @ 1300 nm	n/a

Configuration with dual-output A or dual-output B is also available.
Simultaneous mode: > 1 W @ 920 nm, > 1 W @ 1100 nm, and > 2.5 W @ 1025 nm.
Speficied at 920 nm, 1100 nm, and 1025 nm, respectively.
IR pulse duration determined assuming sech2 shape.
Beam pointing deviation over the entire tuning and GDD control range.
Expressed as NRMSD (normalized root mean squared deviation); with less than ±1 °C temperature change after 1 h warm up.

Optional wavelength extension (UV – VIS)

	Output A	Output B	Output C
Second harmonic tuning range	340 – 480 nm	480 – 650 nm	n/a
Conversion efficiency at peak	> 30%		n/a

Environmental Requirements

	Output A	Output B	Output C
Altitude	< 2000 m
Temperature, operating	18 – 30 °C
Temperature, storage	10 – 35 °C
Relative humidity, operating	< 80% (non-condensing)

Dimensions

	Output A	Output B	Output C
Laser head (L × W × H)	806 × 528 × 311 mm
Rack for power supply and chiller (L × W × H)	642 × 553 × 673 mm

Performance

CRONUS-2P tuning curve

CRONUS-2P GDD control range

CRONUS-2P relative intensity noise (RIN)

Stability

CRONUS-2P output power stability at 900 nm

CRONUS-2P long-term beam position stability at 950 nm

CRONUS-2P long-term beam direction stability at 950 nm

CRONUS-2P long-term beam position stability at 1100 nm

CRONUS-2P long-term beam direction stability at 1100 nm

Drawings

CRONUS-2P drawing

Publications

Effect of tissue fixation on the optical properties of structural components assessed by non-linear microscopy imaging

M. A. Markus, D. P. Ferrari, F. Alves, and F. Ramos‑Gomes, Biomedical Optics Express 8 (14), 3988 (2023).

Electronically preresonant stimulated Raman scattering microscopy in the visible

A. J. X. Choorakuttil, A. Pruccoli, M. J. Winterhalder, P. Zirak, D. Gudavičius, G. Martynaitis, D. Petrulionis, D. Samsonas, L. Kontenis, and A. Zumbusch, Applied Physics Letters 16 (123), 163701 (2023).

Stimulated Raman scattering CRONUS-2P

Ketogenic diet uncovers differential metabolic plasticity of brain cells

T. Düking, L. Spieth, S. A. Berghoff, L. Piepkorn, A. M. Schmidke, M. Mitkovski, N. Kannaiyan, L. Hosang, P. Scholz, A. H. Shaib et al., Science Advances 37 (8) (2022).

Nonlinear microscopy CRONUS-2P