Leica Microsystems Cms Gmbh

Leica Microsystems Heidelberg Gmbh

Bernd Widzgowski

Holger Birk

Volker Seyfried

Frank Schreiber

Johann Engelhardt

Patric Mrawek

Werner Knebel

Vishnu Vardhan Krishnamachari

Wernher Fouquet

Frank Hecht

Arnold Giske

Lioba Kuschel

Hilmar Gugel

Frank Sieckmann

Marcus Dyba

William C Hay

Roland Seifert

Lars Friedrich

Juergen Schneider

Jochen Sieber

Holger Nissle

Ludger Schulte

William Hay

Holger Dr Birk

Florian Warken

A method for driving an acousto-optic element with an acousto-optic crystal and a piezoelectric transducer for setting the acousto-optic crystal in mechanical vibration includes driving the piezoelectric transducer with a drive signal with at least one drive frequency. The at least one drive frequency in alternation takes on a plurality of different values around a center frequency during a passage of a mechanical vibrational wave through the acousto-optic crystal, such that a grating that is produced owing to density fluctuations in the acousto-optic crystal exhibits different grating spacings at the same time.

Method and signal generator for driving an acousto-optic element

A method for evaluating a single-photon detector signal includes duplicating the single-photon detector signal into a first and a second signal. The first signal is processed and the second signal is either not processed or is processed in a manner different from the first signal. A differential signal is formed between the unprocessed or differently processed second signal and the processed first signal. The differential signal is evaluated to determine pulse events.

Method for evaluating a single-photon detector signal

An electric circuit for driving an acousto-optic crystal includes a piezoelectric converter configured to drive the acousto-optic crystal to vibrate mechanically. A signaling cable is configured to conduct a first electrical alternating-current signal and a second electrical signal. The electric circuit further includes a first frequency-separating filter and a second frequency-separating filter, each of the frequency-separating filters having an input, a high-frequency output and a low-frequency output. The input of the first frequency-separating filter and the input of the second frequency-separating filter is connected to the signaling cable, and the high-frequency output of the second frequency-separating filter is connected to the piezoelectric converter.

Electric circuit and method for driving an acousto-optic crystal

A method for counting photons using a photomultiplier includes obtaining a measurement signal from a raw signal produced by the photomultiplier by correcting the raw signal for a noise signal and/or an offset, wherein an incident photon produces a pulse in the raw signal. The measurement signal is integrated over time to form an analog integrated measurement signal. A number of photons that are incident in the photomultiplier is ascertained by comparing a value of the analog integrated measurement signal to an integral proportionality value which corresponds to a specific number of photons incident in the photomultiplier.

Method for counting photons by means of a photomultiplier

A fluorescence-lifetime imaging microscopy method with time-correlated single-photon counting includes using excitation light pulses separated in each case by a measurement interval to excite a sample to emit fluorescence photons. A detector signal that represents the captured fluorescence photons is generated. Detection times are determined based on the detector signal. Imaging is performed based on the detection times. The detection times of all captured fluorescence photons are compiled in a first data memory, common to a plurality of image pixels. The detection times of only those fluorescence photons which were captured in a predetermined number within the respective measurement intervals are compiled in a second data memory, common to the same plurality of image pixels. The detection times compiled in the data memories are combined within a calculation step. The results of the calculation step are stored in a third data memory.

Fluorescence-lifetime imaging microscopy method having time-correlated single-photon counting

A method forms a digital value from a clock signal and a digital data signal. The method includes sampling the clock signal in order to obtain a clock signal digital value sequence and sampling the digital data signal in order to obtain a data signal digital value sequence. Sampling points are ascertained from the clock signal digital value sequence, at which data signal digital values are extracted from the data signal digital value sequence. The digital value is formed from the data signal digital values.

Method for forming a digital value from a clock signal and from a data signal

A light/voltage converter circuit for converting intensity fluctuations of light into an alternating voltage measurement signal includes a photodiode configured to detect the light and a transformer comprising a primary coil and a secondary coil. The primary coil is connected in a series circuit to the photodiode, and the alternating voltage measurement signal is applied to the secondary coil. An electrical network is configured to block direct current and conduct alternating current. The electrical network is connected in parallel with the series circuit consisting of the primary coil of the transformer and the photodiode.

Light/voltage converter circuit for converting intensity fluctuations of light into an alternating voltage measurement signal

A fluorescence lifetime imaging microscopy method with time-correlated single photon counting includes periodically exciting a sample to emit fluorescence photons, with a measurement interval being defined between each two successive excitation light pulses. A value characterizing fluorescence decay behavior is determined based on detection times of detected fluorescence photons, and imaging is performed based one the value. An analog detector signal is sampled within a plurality of sampling intervals within a respective one of the measurement intervals and is converted into a sequence of discrete signal values associated with the sampling intervals. It is determined based thereon whether more than a predefined number of fluorescence photons has been detected within the respective measurement interval. If more than the predefined number of fluorescence photons has been detected, the respective measurement interval is discarded in the step of determining the value characterizing the fluorescence decay behavior.

Fluorescence lifetime imaging microscopy method having time-correlated single-photon counting, which method permits higher light intensities

The present invention relates to a method for measuring the lifetime of an excited state in a sample, in particular a fluorescence lifetime, and to an apparatus for carrying out such a method. First, an excitation pulse is generated and a sample region is illuminated with the excitation pulse. Then, a first digital data sequence is generated which is representative of the power-time profile of the excitation pulse, and a first switching instant is determined from the first digital data sequence. Moreover, the detection light emanating from the sample region is detected by a detector, and a second digital data sequence is generated which is representative of the power-time profile of the detection light, and a second switching instant is determined from the second digital data sequence. Finally, the time difference between the first and second switching instants is calculated.

Method for measuring the lifetime of an excited state in a sample

An arrangement for use in illuminating a sample in SPIM microscopy includes an illumination objective configured to receive and focus a light strip or a quasi-light strip. The quasi-light strip is made up of a light bundle continuously moved back and forth in a light-strip plane. A deflection apparatus is configured to deflect the light strip or the quasi-light strip, after the light strip or the quasi-light strip has passed through the illumination objective, in such a way that the light strip or the quasi-light strip propagates at an angle different from zero degrees with respect to an optical axis of the illumination objective. The illumination objective and the deflection apparatus are arranged movably relative to one another.

Arrangement for use in the illumination of a specimen in SPIM microscopy

The present invention relates to a confocal laser scanning microscope () having an illumination device () that comprises a laser light source () that is configured to illuminate a sample (), and a control application circuit () for the laser light source () which is configured to output a pulsed control application signal () in order to supply the laser light source (), the control application circuit () being configured so that it determines both a pulse amplitude (A) and a pulse width (W) of at least one pulse of the pulsed control application signal () as a function of at least one input variable (S).

Confocal laser scanning microscope having a laser light source to which pulsed control is applied

A method and an apparatus for examining a sample. The apparatus has a light source for generating excitation light in pulses which occur in succession at an excitation pulse frequency, for illuminating a sample region with the excitation pulse, and having a detector for detecting the detection light emanating from the sample region. The apparatus is characterized in that, for each detected photon of the detection light, the detector generates an electrical pulse and thereby a sequence of electrical pulses, and an analog-digital converter is provided that generates a digital data sequence by sampling the sequence of electrical pulses at a sampling rate.

Method and apparatus for examining a sample

A detector apparatus that is embodied to receive light and to generate electrical signals has a housing and a detector arranged in the housing. The detector includes a light sensor that is embodied to receive light and to release electrons. The light sensor is at a lower electrical potential level than the housing; and that the detector is in thermally conductive contact with the housing via an electrically insulating intermediate arrangement, the thermal conduction direction inside the housing being opposite to the light propagation direction of the light to be detected.

Detector apparatus

A microscope, in particular a confocal microscope, has one or more lasers for generating an illumination light for a sample and has a detection device for detected signals from the sample. The detection device includes multiple adjustable spectral detection channels for the detection of predefinable different wavelength regions, and is configured and refined in the interest of particularly versatile utilization in consideration of a wide variety of phenomena, with particularly good separation of the phenomena in the context of investigation, in such a way that multiple temporal detection windows are respectively settable for the spectral detection channels.

Microscope and a method for examining a sample using a microscope

The invention relates to a method for investigating a sample with regard to the lifetime of an excited state, in particular a fluorescence lifetime, and/or with regard to a property of a sample which is correlated with a lifetime of an excited state, in particular with a fluorescence lifetime, a sample region being illuminated with a sequence of excitation light pulses. The method is characterized in that the light quantity and/or number of photons of the detected light, in particular fluorescent light, proceeding from the sample region is measured temporally between the excitation light pulses exclusively within a detection time window in each case, at least two detection time windows having different temporal lengths.

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Dossenheim, Germany

Bernd Widzgowski