Thin-Disk Laser CEP Control via Segmented Pump Diodes

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

High-power thin-disk pulse laser devices face challenges in stabilizing carrier-envelope phase (CEP) and intensity noise due to noisy oscillator interactions, which existing methods fail to address effectively, especially with conventional constant current power supplies that lack high stability and dynamic control.

Innovation Solution

The method involves pumping a thin-disk laser medium with multiple continuous wave pump laser diodes, including at least one modulated diode for broadband control of CEP and intensity, and one stable diode for constant power, using separate current sources to achieve precise control without impairing pulse stability, and combining their outputs optically to minimize noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If conventional constant current power supplies are used to pump high-power laser diodes, then high power output is achieved, but current stability and dynamic control capability deteriorate

Engineering Contradiction:
Improvepump powerVSAvoidcurrent stability
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The pump laser diode array is divided into multiple independently controllable diode channels, each driven by its own constant current source. This segmentation allows individual control of each diode's contribution to the total pump power, enabling precise stabilization of the aggregate output while maintaining high total power. Each channel can be independently optimized for stability without compromising the others.

Inventive Principle:
Principle #1Segmentation

2Power

If conventional constant current power supplies are used, then high power output is achieved, but bandwidth for CEP stabilization deteriorates

Engineering Contradiction:
Improvepump powerVSAvoidcontrol bandwidth
Core Design Contradiction:
PowerVSAdaptability or versatility

Solution Approach 1:

The system implements dynamic control by enabling independent modulation of individual laser diode channels at high bandwidths (tens of kHz to MHz range). This dynamic capability allows rapid adjustment of pump power distribution among channels to compensate for CEP fluctuations and intensity noise, providing the adaptability needed for active stabilization while maintaining high average pump power.

Inventive Principle:
Principle #15Dynamics

3Power

If multiple laser diodes are used for pumping, then pump power is increased, but mutual interaction and noise between diodes worsen

Engineering Contradiction:
Improvepump powerVSAvoidnoise from mutual interaction
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

By segmenting the pump source into independently controlled diode channels with separate current sources, the system can optimize each channel's operating parameters to minimize interaction noise. The independent control allows for balanced power distribution and phase coordination among diodes, reducing mutual interference effects while achieving high total pump power.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system utilizes parameter changes by independently adjusting the drive current, wavelength, and power contribution of each laser diode channel. This enables optimization of each diode's operating point to minimize noise generation and mutual interaction, while the aggregate effect provides high stable pump power for the thin-disk laser medium.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If high-power laser diodes are modulated for CEP control, then CEP stabilization is achieved, but intensity noise increases due to noisy operation

Engineering Contradiction:
ImproveCEP stabilityVSAvoidintensity noise
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The system segments the modulation function across multiple low-power laser diode channels rather than modulating a single high-power diode. Each channel contributes a stable, low-noise pump component, and their coherent summation provides the total pump power needed. This segmentation allows CEP control through low-noise channels without introducing the intensity noise that would result from modulating high-power diodes.

Inventive Principle:
Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach provides reliable and precise control of CEP and intensity noise, enabling power scalability and high stability, even at high powers, with low dependency on polarization and beam quality, suitable for applications like frequency combs and high-field physics.

Implementation Method 1

controlling a carrier-envelope phase (CEP) of the output pulses... the at least one modulated laser diode is modulated by an analogue control of the drive current

Methodology Applied
Scientific EffectCarrier-envelope phase modulation:

Implementation Method 2

a thin disk laser medium is pumped with multiple continuous wave (cw) pump laser diodes

Methodology Applied
Scientific EffectOptical pumping: Absorption (EM radiation)

Data Source

PatentEP2866311B8Method and device for controlling a carrier-envelope phase and/or an intensity of output pulses of a pulse laser device
Publication Date: 2018.06.27 LUDWIG MAXIMILIANS UNIV MUNCHEN

AI summary

A method of controlling output pulses of a pulse laser device (100) including a thin-disk laser medium (10), in particular controlling a carrier-envelope phase and/or an intensity noise of the output pulses, includes the steps of pumping the thin-disk laser medium (10) of the pulse laser device (100) with multiple pump laser diodes (21, 22, 23), which include at least one modulated laser diode (21, 22) which is powered by a current source (31, 32) with modulation capability, and controlling the output pulses by modulating the output power of the at least one modulated laser diode (21, 22), which is modulated by controlling a drive current thereof, wherein the pump laser diodes further include at least one stable laser diode (23), which has a constant output power, and the output power of the at least one modulated laser diode (21, 22) is smaller than the whole output power of the at least one stable laser diode (23). Furthermore, a pulse laser device (100), being adapted for creating output pulses, in particular having a controlled carrier-envelope phase and/or intensity noise, is described.