1932-2026

This is a nice memorial written by Manfred Helm and copied here from LinkedIn (https://www.linkedin.com/posts/manfredhelm_with-this-post-i-would-like-to-commemorate-activity-7502383359873114112-H9OT). Carl was an active member of the IRMMW-THz community from its inception in the mid 1970s through to his retirement.

Reproduced from post by Manfred Helm (Sept. 26, 2026):

With this post I would like to commemorate Carl R. Pidgeon, Professor Emeritus at Heriot-Watt University in Edinburgh, Scotland, who passed away a few days ago, on 3 September 2026, at the age of 88.

Carl became famous in the mid sixties, through what has soon been called Pidgeon-Brown model, to calculate the magnetoabsorption in narrow-gap semiconductors (by now cited nearly 1000 times; please see the first comment for links). 

For me he was a great mentor and dear friend, who influenced my career significantly. During my PhD thesis at Universität Innsbruck in the mid 1980s, I had the chance to visit his lab twice for a week to use his electrically pulsed far-infrared gas laser system, providing an order of magnitude more peak power than standard cw systems (for nonlinear cyclotron resonance experiments). In the early nineties he asked me whether I would like to do experiments at the newly established FELIX free-electron laser (FEL) in The Netherlands. (He had been strongly involved in the UK FEL program; after its cancellation an undulator was given to FELIX, which laid the ground for a strong UK involvement in FELIX, now HFML-FELIX). The subsequent experiments (on intersubband transitions in quantum wells) and the FEL experience I acquired turned out to be essential for my career, in particular for getting the position I held at Helmholtz-Zentrum Dresden-Rossendorf (HZDR). During that beamtime Carl brought his young student Benedict Murdin, who also became a lifelong friend (of mine and even more so, of Carl). 

Describing Carl’s personality to people who didn’t know him, is probably impossible, and I won’t  attempt to do so here. He was simply unique. The photo was taken at one of our last meetings, in 2018. In the last few years he didn’t travel much anymore, in particular not by aeroplane. 

A long and exciting life has come to an end. Thank you, Carl. You will stay in our minds and our hearts.