公开(公告)号：US12222484B2

公开(公告)日：2025-02-11

申请号：US17673959

申请日：2022-02-17

Applicant: TOPTICA Photonics AG

Inventor： Christian Rausch ,  Alf Rieckmann ,  Manfred Hager ,  Jörg Lembach

IPC: G02B21/00 ,  H05B45/22 ,  H05B45/32

Abstract: The invention relates to an illumination device, in particular for a confocal microscope. The object of the invention is to provide an illumination device which operates with a plurality of current-modulated semiconductor-based light sources, in which the light emission is as free as possible from distortions due to dynamic delays of the light emission in the output beam. To this end, the proposed illumination device comprises: two or more semiconductor-based light sources, in particular laser diodes, which are designed to emit light at different wavelengths, a combining unit, which is designed to combine the light emissions of the light sources into a single output light beam, and a driver unit connected to the light sources, which driver unit is designed to synthesise an operating current signal, which is supplied to each of the light sources, from at least one control signal, which specifies the temporal course of the light emission of each of the light sources, by means of digital signal processing, wherein the driver unit impresses a compensation signal on each of the operating current signals, which compensation signal at least partially compensates for a specific dynamic delay of the light emission of the particular light source.

公开(公告)号：US11881682B2

公开(公告)日：2024-01-23

申请号：US17348971

申请日：2021-06-16

Applicant: TOPTICA Photonics AG

Inventor： Martin Enderlein ,  Manfred Hager ,  Thomas A. Puppe ,  Frank Lison

IPC: H01S3/13 ,  H01S5/0687 ,  H01S5/06 ,  H01S5/14 ,  H01S3/139 ,  H01S5/00

CPC classification number: H01S5/0687 ,  H01S3/1305 ,  H01S3/139 ,  H01S5/0092 ,  H01S5/0604 ,  H01S5/14

Abstract: The invention relates to a method for modulating the resonant frequency of an optical resonator (1) in accordance with a periodic, not necessarily harmonic, modulation signal (Umod(t)). Fast modulation of an optical resonator is intended to be made possible in which the current resonant frequency follows the modulation signal (Umod(t)) as precisely as possible, and specifically at a fundamental frequency of the modulation signal in the kHz range. To do this, the invention proposes the following method steps:



deriving an error signal (E(t)) from a light field circulating in the resonator (1), wherein the error signal (E(t)) indicates the deviation of the optical frequency of the light field from a target value,
deriving a first actuating signal (S1(t)) from the error signal (E(t)) by means of a controller (6),
generating a second actuating signal (S2(t)), which has actuating-signal components at one or more harmonics (fmod, 2fmod, . . . ) of the fundamental frequency (fmod) of the modulation signal (Umod(t)), and
applying a superposition signal made up of the first and the second actuating signal (S1(t), S2(t)) to an actuator (3) that changes the optical path length of the resonator (1). In other words, the invention makes use of a combination of control and narrow-band feed-forward control tuned to the spectrum of the modulation signal (Umod(t)) and of the error signal (E(t)) to modulate the resonant frequency. Preferably, the feed-forward control used for generating the second actuating signal (S2(t)) is automatically adapted in accordance with the error signal (E(t)). In addition, the invention relates to an accordingly configured optical system.