Method and signal generator for controlling an acousto-optic element

Patent metadata

Field	Value
Publication number	US-12468186-B2
Application number	US-201816607367-A
Country	US
Kind code	B2
Filing date	Apr 25, 2018
Priority date	Apr 25, 2017
Publication date	Nov 11, 2025
Grant date	Nov 11, 2025

Abstract

A method for actuating an acoustooptical element includes generating an actuation signal by a direct digital synthesis (DDS) method using a signal value sequence made up of at least two frequency components. A signal generator for actuating an acoustooptical element is configured to perform the method. An arrangement includes the signal generator and the acoustooptical element. A microscope includes the arrangement.

First claim

The invention claimed is:

1 . A method for actuating an acoustooptical element, the method comprising:
generating an actuation signal by a direct digital synthesis (DDS) method using a signal value sequence made up of at least two frequency components that are overlaid in the signal value sequence such that the actuation signal contains at least two frequencies that overlap in time.

2 . The method as claimed in claim 1 , wherein the signal value sequence is made up of integer periods of each of the at least two frequency components.

3 . The method as claimed in claim 2 , wherein each of the at least two frequency components comprises a respective finite set of signal values, each respective finite set of signal values defining a frequency of a sinusoidal oscillation, and each integer period corresponding to an entirety of each respective finite set of signal values.

4 . The method as claimed in claim 1 , wherein the signal value sequence is made up of at least three frequency components, and wherein at least one pair of two of the frequency components is at a same frequency interval from one another as another pair of two of the frequency components.

5 . The method as claimed in claim 4 , wherein each even number of pairs of two of the frequency components is at the same frequency interval from one another.

6 . The method as claimed in claim 1 , wherein the signal value sequence is made up of an uneven number of frequency components.

7 . The method as claimed in claim 1 , wherein a phase of at least one of the frequency components is prescribed at a specific time in order to alter a maximum in the signal value sequence.

8 . The method as claimed in claim 1 , wherein a phase increment is prescribed for sweeping the signal value sequence based on a temperature of a crystal of the acoustooptical element.

9 . The method as claimed in claim 1 , wherein the frequency components are prescribed such that the signal form is repeated after a time less than or equal to a threshold value.

10 . The method as claimed in claim 9 , wherein the threshold value is 250 ns.

11 . The method as claimed in claim 1 , wherein a bandwidth of the acoustooptical element is adjusted.

12 . The method as claimed in claim 1 , wherein multiple illumination points are produced from an illuminating light illuminating the acoustooptical element.

13 . The method as claimed in claim 12 , wherein a phase increment is prescribed for sweeping the signal value sequence to prescribe the positions of the illumination points.

14 . A signal generator for actuating an acoustooptical element, the signal generator being configured to perform the method as claimed in claim 1 .

15 . An arrangement comprising at least one signal generator as claimed in claim 14 and an acoustooptical element.

16 . The arrangement as claimed in claim 15 , wherein the acoustooptical element is one of an acoustooptically tunable filter, an acoustooptical modulator, an acoustooptical deflector, an acoustooptical beam splitter and an acoustooptical beam merger.

17 . A microscope having the arrangement as claimed in claim 15 .

18 . The method as claimed in claim 1 , further comprising:
sweeping the signal value sequence by a phase increment using an interpolator such that a frequency ratio between the at least two frequency components is maintained independent of a size of the phase increment.

19 . The method as claimed in claim 18 , wherein the signal value sequence is stored in a memory device, and wherein the interpolator is driven by a clock generator to output the at least two frequency components to a digital to analog converter.

20 . The method as claimed in claim 1 , further comprising actuating the acoustooptical element using the actuation signal.

21 . The method as claimed in claim 1 , further comprising retrieving the at least two frequency components from a table stored in memory, wherein the signal value sequence stored in the table comprises at least a first number of periods at a first frequency overlaid with a second number of periods at a second frequency.

Assignees

• Leica Microsystems

Inventors

• Birk Holger

Classifications

• G02F1/33

  Acousto-optical deflection devices {(circuit or control arrangements therefor G02F1/113)} · CPC title

• G02F1/116

  using an optically anisotropic medium, wherein the incident and the diffracted light waves have different polarizations, e.g. acousto-optic tunable filter [AOTF] (G02F1/125 takes precedence) · CPC title

• G02F1/113 Primary

  Circuit or control arrangements · CPC title