Fluorescence spectrophotometer (first photon counting)

Fluorescence spectrophotometer (first photon counting)Intended to explore the fluorescence attenuation of dim samples. Due to the typical time scale of fluorescence phenomena spanning 10 ^ -8 seconds, faster settings are needed to observe such a rapid process.
The inspected sample is excited by picosecond laser pulses. After excitation, the system measures the flight time of individual photons emitted by the sample. Photons fly over the monochromator and reach the photomultiplier tube. The shape of induced fluorescence pulses in the sample was reconstructed based on the statistical data of flight time evaluated for each captured photon. A key requirement for the performance of FPC-TDC fluorescence spectrophotometer is a low probability of photons reaching the detector (<10% per pulse). Therefore, this instrument is unparalleled in studying materials with low fluorescence yield.

Fluorescence spectrophotometer (first photon counting)First photon counting, suitable for samples with low fluorescence yield

Parameters measured by instruments:

The relationship between fluorescence time decay and light wavelength and polarization potential (in the case of electrochemical samples),

Emission fluorescence spectrum/

I-V characteristics/

Open circuit potential (OCP),

Current flowing through the sample

Fluorescence spectrophotometer, the system comprising:

sample room

picosecond laser

Grating for UV, VIS, and IR ranges,

photomultiplier tube

potentiostat

Electrochemical colorimetric dish with platinum electrode and reference Ag/AgCl electrode,

Time to Digital Converter

specification

picosecond laser

波长： 405 nm、450-460 nm、630-640 nm、

Half width of pulse duration: 150 ÷ 200 ps,

Maximum pulse repetition frequency: 1MHz,

Pulse light power: 60 mW,

Trigger type: TTL up to 1 MHz,

Power supply: 12 VDC,

monochromator

Spectral range: 200 ÷ 1200 nm,

Electric slit, controlled by software,

Entrance and output slit opening range: 0 ÷ 5 mm,

Electric internal shutter, capable ofCut off the light beam and control it through software,

photomultiplier tube

Anode to cathode voltage range: up to 2500 V,

Spectral range: 300 ÷ 650 nm,

Transmission time extension (FWHM): 160 ps,

Rise time: 0.7 ns.

Time to Digital Converter

Time resolution: 27 ps,

Maximum measurement time: 500 ns,

An additional reference channel for minimizing laser jitter,

Maximum pulse rate:

– 500 kHz， 2-channel measurement: sampling and reference,

– 1 MHz， 1-channel measurement,

Internal trigger frequency: 1 kHz ÷ 1 MHz),

External trigger mode, TTL input

potentiostat

Bias potential range: -5 V ÷ 5 V,

Current range: 10 nA, 100 nA, 1 μ A, 10 μ A, 100 μ A, 1 mA, 10 mA

Current resolution: from 1 pA to 100 nA (depending on the range),

controller

Connected to PC: via USB 2.0,

RS485 socket for controlling equipment