HALCYONE Fire
Femtosecond Fluorescence Upconversion and TCSPC Spectrometer
HALCYONE Fire is the next generation, fully automated time-resolved Fluorescence Spectrometer featuring our patented automated beam alignment system (Patent No.: US 10,209,131). It consists of two units: Fluorescence Upconversion and Time Correlated Single Photon Counting (TCSPC). In the upconversion mode HALCYONE Fire can measure fluorescence decays with femtosecond time resolution over an 8 ns time window. The TCSPC unit allows for measuring fluorescence lifetimes with picosecond time resolution over longer time windows.
Fluorescence spectral range
The exact fluorescence detection range depends on the laser wavelengths used for excitation and gating as the scattered laser light can interfere with the fluorescence signal. While the excitation wavelength is typically tuned to match the absorption of a specific chromophore, the gate wavelength normally corresponds to the fundamental output of the laser. The residual excitation light after the sample can usually be blocked with an optical filter. However, the detection of the upconverted fluorescence signal is often obscured by the scattered gate and its harmonics leaking into the detector. Therefore, for Ti:Sapphire lasers with the center wavelength of 800 nm detecting the fluorescence around 267 nm, 400 nm and 800 nm is very difficult. The same thing happens for Yb lasers with the center wavelength of 1030 nm – fluorescence around 343 nm, 515 nm, and 1030 nm is often undetectable.
One way to mediate such spectral “blind spots” is to use an OPA for gate pulse generation. Having access to wavelength tunable gate allows to measure fluorescence across the whole range of the spectrometer without any gaps.
Fluorescence can be measured across the following spectral ranges:
Spectral Range With Ti:Sapphire laser (center λ ~800 nm) With Yb laser (center λ ~1030 nm) With optional gate OPA UV
270 – 350 nm
260 – 340 nm
VIS
450 – 770 nm
370 – 950 nm
340 – 1000 nm
NIR
> 850 nm
> 1100 nm
8 ns time window
The nanosecond window is achieved by using a direct-drive high speed optical delay line. Custom designed mounts are employed for the delay line optics to increase the beam alignment reproducibility and the overall reliability. This delay line features high resolution as well as high speed. Scanning at high speeds is very important because it allows for pseudo-random stepping without a significant increase in the experiment time. This type of stepping is very useful for minimizing the effects of laser instability and sample degradation.
Optical delay line specifications:
Time window: 8 ns
Resolution: 14 fs
Minimum step size: 2.8 fs
Max. speed: >10 ns/s
Acceleration: > 260 ns/s^2
Automated alignment time: 3-5 min
Beam pointing drift: <10 µm over 8 ns delay range
Detectors
HALCYONE Fire is available with two detector options: single wavelength PMT or multi-wavelength CCD.
At any time HALYCONE Fire can be upgraded to include the other detector option to extend the capabilities of the instrument.
Single photon counting PMT with a monochromator. This detector enables HALCYONE to measure a single wavelength fluorescence signal at a particular time delay. The fluorescence signal can be measured as a function of time or wavelength by scanning an optical delay line or a computer-controlled monochromator, respectively. To maximize the sensitivity at each fluorescence wavelength, the phase matching angle of a non-linear crystal angle is automatically adjusted by a computer-controlled rotation stage.This PMT is capable of detecting single photons and offers the highest sensitivity. However, it can register only one photon per laser pulse and therefore is most beneficial at higher rep rates (tens of kHz and above). We recommend this detector for experiments where only select kinetics or spectra need to be acquired (no full time-wavelength-intensity surface is needed), and a high rep rate laser is available.
Thermoelectrically cooled CCD camera (1024×255 pixels) with a high throughput imaging spectrograph. While not quite as sensitive as a single photon counting PMT, this detector can capture a broad spectrum at once and also register multiple photons per pixel, per laser pulse, thus providing a large dynamic range even at lower rep rates (~1 kHz). We recommend this detector for experiments where it is necessary to monitor the fluorescence spectral evolution as well as resolve decays at individual wavelengths. For example, energy transfer processes, solvation dynamics, vibrational relaxation, etc.
Computer controlled non-linear crystal
In order to maximize the upconverted signal intensity the non-linear crystal needs to be rotated to a certain angle with respect to the fluorescence and gate beams. To simplify the user experience, this angle is automatically adjusted by the HALCYONE software when either a CCD or a PMT detector is used.
While the CCD itself can detect a fluorescence signal over a broad range, the non-linear crystal has a rather limited spectral bandwidth at each phase matching angle. Therefore, in order to measure a full fluorescence spectrum, one needs to rotate the non-linear crystal over a range of angles corresponding to the spectral window of interest. This is achieved by putting the non-linear crystal on a computer-controlled rotation stage. The crystal angles are factory calibrated, so the user does not need to worry about determining a correct crystal angle. Based on the selected spectral region, the HALCYONE software automatically calculates the crystal angle scanning range. Simultaneously the crystal rotation speed is calculated based on the CCD integration time and the angular range. All these operations are performed automatically, so the only parameter a user needs to specify is the fluorescence spectral range.
A similar approach for the crystal rotation is used for the PMT detector at each individual fluorescence wavelength.
Emission spectral range
In Time Correlated Single Photon Counting the emitted photons are registered directly, therefore the observed spectral range is determined only by the detector. The choice of detector depends on the required wavelength and time resolution. Ultrafast Systems offers the following TCSPC detector options:
Detector IRF Spectral Range HA-PMT-200
200 ps
230 – 700 nm
HA-PMT-50
50 ps
220 – 650 nm
HA-MPD
50-200 ps (depends on wavelength)
400 – 900 nm
HA-PMT-NIR
400 ps
950 – 1400 nm
The above detectors are sufficient for most applications. Additional detectors can be integrated on request.
Halcyone Fire features versatile and user-friendly LabVIEW based software for instrument control and data acquisition. The software allows for full experiment automation, so no input from the user is required for the whole experiment duration.
The software is also very user-friendly and versatile:
Supports a PMT detector with a computer-controlled monochromator.
Supports a CCD detector with a high throughput spectrograph.
Takes into account the pump and fluorescence wavelengths and automatically adjusts the computer controlled non-linear crystal’s angle.
Automated alignment of the optical delay line.
Computer controlled switching between UV, VIS, and NIR fluorescence spectral ranges.
Supports computer controlled translating sample holder.Supports pump beam shutter.
Supports motorized filter wheel for automated pump intensity control.
Saves every individual kinetic scan, so if experiment is aborted (due to laser fluctuations, power outages, etc.) all previous scans are not lost.
Threshold adjusted automatic probe intensity spike rejection – advanced setting which collects data points again if the probe is not stable.
API (Application Programming Interface) for HALCYONE Fire is provided for further experiment customization and integration with external applications.
商品属性 [波长范围] 270-1600 nm