Single-shot, high repetition rate detection of the Carrier-Envelope-Phase of ultrashort laser pulses

Introduction

The interaction of short laser pulses with matter often depends on the Carrier-Envelope-Phase (CEP), which is the offset between the maximum of the electric field and the envelope of the pulse. For high-repetition-rate laser systems, this phase can usually only be measured as an average quantity.

Proposed Method

We propose a novel analog method to measure the CEP of ultrashort laser pulses in single-shot and for every laser shot at high repetition rate (hundreds of kHz to MHz). While conventional approaches use slow array detectors and computationally expensive calculations, we perform the measurement via optical Fourier transform, virtually not imposing any speed limitations.

This approach also opens up new avenues for CEP stabilization, possibly making most of today's complicated and expensive stabilization equipment obsolete. A patent application, securing our IP, has been submitted.

Collaboration

The project will be conducted together with our long-standing commercial partner, Sphere Ultrafast Photonics. Sphere has a strong position in the ultrafast laser market, defining an efficient path for commercialization.

Development of Detectors

We plan to develop two different kinds of CEP detectors:

1. The analog detector
2. A simplified digital detector working up to 100 kHz for less demanding applications

The detectors will be extensively tested and benchmarked against each other with a number of ultrafast laser sources in Lund and at Sphere.

Inspiration and Background

The original idea for analog CEP detection was inspired by our research in attosecond science, supported by the ERC advanced grant QPAP Quantum Physics with Attosecond Light Pulses (884900), which requires CEP control.

The lack of existing techniques for the challenging repetition rate of our laser source (200 kHz) stimulated the ideas presented in this proposal, which we now would like to explore as a proof-of-concept.