The Electronics

 

            Time Correlated Single Photon Counting measurements are made with a Becker-Hickl SPC-630 PCI card in a PC using the "reversed start/stop mode". A fast photomultiplier tube (FWHM = 150ps) is used as the emission detector and generates the timing "START" signal while a fast photodiode module monitors the excitation pulses and generates the timing "STOP" signal. The motor-driven filter wheel and polarizer are both driven by the Becker-Hickl STP-240 Stepper Motor ISA PC card. A data acquisition board is used for temperature monitoring.

 

            TCSPC Lifetime Acquisition board

                        Becker-Hickl SPC-630 PCI card

                                    Single board TCSPC with input amplifiers, Constant Fraction Discriminator, Time-Amplitude Converter, and Multichannel Analyzer

                                    Up to 8MHz counting rate

                                    Standard TCSPC histogram mode as well as raw photon data ("BIFL") mode

                                    On-board memory of up to 64 curves of 4096 channels each

                                    Constant fraction discriminator electrical resolution of 5ps RMS, with TAC channel width down to 813 femtoseconds

                                    Multi-detector routing options

                                    Labview (National Instruments) and DLL libraries available

 

            Detectors

                        Becker-Hickl PD-400 Visible Photodiode Module

                                    Response from 350nm to 1050nm

                                    Pulse Width 400ps FWHM

                                    Detector Spot size > 0.5 mm diameter

 

                        Becker-Hickl PD-400 UV Photodiode Module

                                    Response from 225nm to 340nm

                                    Pulse Width 400ps FWHM

                                    Detector Spot size > 0.25 mm diameter

 

                        Becker-Hickl PMH-100-3 Photomultiplier Module

                                    Response from 185nm to 650nm

                                    Transit Time Spread 150ps FWHM

                                    Detector Spot size 8 mm diameter

                                    Single +12 Volt Supply

 

            Stepper Motor Controller/Driver board

                        Becker-Hickl STP-240 ISA card

                                    Single Board Controller and Motor Driver

                                    Two unipolar motor channels up to 1 amp per phase

                                    Controlled drectly from Becker-Hickl TCSPC software

                                    Labview (National Instruments)  and DLL libraries available

 

            Custom Connection Box

                        Integrates system connections including TCSPC control signals, Router signals, Shutter Controller, switches, LEDs, and temperature control.

 

            PC

                        Dell Dimension 1.1GHz PCI and ISA board-compatible PC running Windows

 

Last updated August 10, 2003