FROST filter mounted onto a rifle scope with dark dramatic lighting and a black background

CALIBRE DEFENCE LEADERSHIP INTERVIEW WITH SEAN TIPPER, CTO & CO-FOUNDER, SENTINEL PHOTONICS

6 January 2026

CALIBRE DEFENCE LEADERSHIP INTERVIEW WITH SEAN TIPPER, CTO & CO-FOUNDER, SENTINEL PHOTONICS

All credit for this article goes to Sam Cranny-Evans at Calibre. To view this article on the Calibre site, visit here

Professional headshot of a business leader in a suit, smiling against a neutral grey background.

In 2015, as the first phase of the war in Ukraine came to an end, and “separatist forces” took up defensive positions across from the Armed Forces of Ukraine in the Donbass region, Russia began deploying new weapons and technologies to test them. Periodically, the operational security of the troops involved would be lax enough that Western analysts would get a glimpse into what was going on. On one occasion, a team of Spetsnaz, well-equipped with DJI Mavics, anti-drone guns, and commercially available Western marksman rifles were observed making their way into Separatist trenches. Their equipment gave some indication into how sniping had changed in the “anti-terrorist operation,” with drones playing an important role for both finding targets, and finding snipers.

When they occurred, these sightings were fairly well-reported on through social media and defence news outlets, but the use of other weapons less so. In 2016, Ukrainian border guards deployed to a checkpoint near the city of Marinka, which is close to Donetsk city. From their position they looked West, towards Russian-held territory, two with a monocular and one with binoculars. Within a short space of time, they all report seeing a flash of light that left their eyes severely damaged. “The medics that analysed the traumas say that such injuries are caused by lasers,” the Kyiv Post quoted a spokesman for the Border Service as saying in 2018. The two guards using a monocular suffered burns to just one eye, the unfortunate guard using binoculars suffered burns in both.

The border guards were not alone, and the Ukrainian military told the Kyiv Post that several other soldiers had suffered similar injuries since 2014. “We are probably talking here about a retro detection device,” Sean Tipper, the CTO of Sentinel Photonics, and former engineer at the UK’s Defence Science and Technology Laboratory (DSTL), told me on a call in August. “Retroreflection is when light reflects off of the focal plane of a scope and back down that path. It’s actually what happens when you shine a light at a cat’s eyes,” Sean explained. Essentially, retroreflection is the optical phenomenon of a surface reflecting light directly back to its source, regardless of the angle at which the light hits the surface. This differs from a standard mirror, which only reflects light back at an equal and opposite angle to the incident light.

“This can happen if laser light is shone onto a sniper scope, so if you see your own laser reflected then you know there is a scope there,” he continued.

Lasers are far from new on the battlefield, the Chieftain main battle tank carried one from 1969, and the US Air Force tested the laser-guided BOLT-117 bomb in Vietnam the year before. But retroreflection detection devices are different, in part because “they can be pulsed at much higher frequencies or they can be at a continuous wave,” Sean explained, before continuing, “there is a nefarious use for retroreflection devices, they can pulse a high power laser back into the optic, which can severely damage the eyeball. They [the manufacturers] state that they are not targeting the eye, they are targeting the optic, and the device would shatter the optic, but it would also damage the eye, causing a hemorrhagic lesion,” he continued. This was in reference to the Laws of Armed Conflict, which prohibit the use of lasers to target humans in this way. This series of events, starting with the unfortunate Ukrainian soldiers, set Sean and his team at DSTL on a path to what is now Sentinel Photonics.

SENTINEL PHOTONICS, PLOUGH SHARES INTO BEAM DIRECTORS

“Myself and my co-founder, Chris Burgess, worked at DSTL for five and 15 years respectively on the electro-optics protection measures team, designing measures to protect optics from lasers on the battlefield,” he recounted. The team successfully developed a new technology to detect lasers, but struggled to find an industry partner that could meet their own, lab-based build standards. “We knew there were systems out there like Russia’s Pap-V, and similar hand-held systems from China that you can buy online, so we took the decision to spin Sentinel Photonics out of DSTL.”

“DSTL has a commercial arm called Ploughshare Innovations that supports tech commercially, they take patented technology and license it out to industry. We tried that with this technology but it didn’t work out,” Sean continued. As a result, Chris and Sean set Sentinel Photonics up in 2019, before officially spinning the organisation out of DSTL in October 2020. “So, the tech is approved by DSTL, but there is no special treatment and they have to compete commercially etc. but the MoD does own a stake in Sentinel, and the IP is in the name of the Secretary of State,” he told me, providing a glimpse into the inner workings of the UK MoD, and its highly capable defence laboratory.

Now the team includes 20 staff members, with 12 in the technical team including Sean. “Our goal is to mitigate the threat on the battlefield, and we are very acutely aware of the lack of protection that exists,” Sean continued. And the list of threats is growing, already it includes laser range finders and designators, such as the system used by Russia’s Orlan-30, which is used to illuminate targets for strikes with the 152 mm Krasnopol laser guided artillery round. A sensor that detects these signals can provide valuable time for a vehicle or its crew to relocate before an engagement is completed. “Now there are high-energy laser weapons designed to counter drones and dazzle optics at tens or hundreds of kilometres, we can help forces detect and respond to them,” Sean said.

THE SENTINEL PHOTONICS SOLUTIONS

FROST filter mounted onto a rifle scope with dark dramatic lighting and a black backgroundFROST® FILTER

The Sentinel Photonics solutions are divided into two categories, detect, and protect. Detection is provided by a number of systems designed for different applications from a personal system through to vehicle-carried. “FROST is our protection solution for scopes and optics,” Sean explained. FROST is designed to be fitted to a rifle scope or optic using standard mounting threads and is available with three levels of protection. The first is “near infrared (NIR) protection, blocking common retroreflection system wavelengths, Level 2 extends protection beyond the NIR in order to also protect against longer wavelength threats. And Level 3 further provides direct laser exposure protection against additional threats,” the company’s website explains.

Small green laser warning device sat on top of a tripod LASERD® MICRO

It is designed to be coupled with a system like Micro, a wearable laser detection system from Sentinel Photonics. MICRO is approximately the size of a GoPro and has a very low false alarm rate, and can be plugged into a dismounted situational awareness system like the Android Team Awareness Kit (ATAK). Sean sees an opportunity for many laser warning receivers to be connected into a command and control system, providing wider awareness across a force. “So, if a helicopter used a laser range finder, it could be detected by many people and give early warning of something coming and then disperse the armour, for example. But you can only do that if you can detect the lasers,” he said. This draws on the company’s ability to provide intelligence on the type of laser that has been detected.

MICRO can tell wavebands apart – SWIR or NIR – some designators work at certain frequencies that can be detected and propagated through a command and control system. Additionally, laser designators will fire a very specific code that can be picked up and dispersed across a unit. That could give an indication of what the system targeting you is,” he explained. This application could grow in importance for unit survivability. Russian units using Ka-52 attack helicopters have caused extensive damage to Ukrainian armoured formations during the 2023 counter-offensive, for example. The 9M120 Ataka missiles that they fire are laser beam riding, which would generate enough energy to trigger a warning on Sentinel’s MAX, laser detection system.

Sentinel Photonics camera-based laser detection system mounted on a tripod, designed for battlefield threat detection and adversary laser source identificationLASERD® MAX

MAX is the product that Sean and Chris were developing at DSTL. “MAX provides warning of retro systems, laser beam riders etc. it is an all-round detector that can find everything that we are aware of on the battlefield. So, a sniper pair could take it with them, for instance, and a range of sensors could be connected to provide enhanced situational awareness,” Sean explained. MICRO is currently actively deployed, and FROST is deployed in Ukraine. “MAX will go through its full launch at DSEI, and it’s already being used by early adopters”

CALIBRE COMMENT

Lasers are increasingly prominent on the battlefield and in the commercial space. In 2023, some 12,000 incidents of people shining laser pens at commercial aircraft were reported, according to the Laser Safety Certification organisation. Those incidents range from distracting to potentially very dangerous. “Pilots don’t know whether or not a laser is dangerous, and you can build goggles to protect against lasers, but not all wavelengths,” Sean explained. This means that flights, including those of rescue helicopters can be cancelled. Sentinel Photonics is looking at the application of its detectors in the civil and commercial space. “We can’t protect you from every wavelength, but we can tell you if it’s a threat,” Sean said.