@bcredman : It works slightly differently. The language in the presentation (text, not video) was quite clear*
Firstly, sniper detection is mostly done with laser flooding of the general area to protect (static) or on a reactive way. The laser interact with the sniper lens with a glaring effect unmasking the Sniper.
Secondly, the counter sniper laser fire a wave train at a very high frequency, in a pulse mode, of high energy. That makes the riffle able to sustain multiple engagements.
Thirdly, this short pulse makes detection by a counter system based on starring sensor very difficult to acquire and track to the point of origin, unless multiple shots are fired without altering location.
Lastly, the effect on the target is skin penetration and diffusion in the internal organs and bones of the target (human) resulting in a painful to lethal internal burns, lacerations or them being punctured (the skin does not reflect such high energy beam like it does with the sun, leaving internal organs to absorb the input energy). .
One example of the end result of non-lethal human subject, is how to blast the synovial fluid in someone knees or ankles with inherent/adjacent calcification of the joints.
Those are nasty systems you DO not want to spread around**
*Note that I am writing this days after reading the presentation and only jumped on your post to quickly make some adjustments to how we can understand how that weapon works.
**more than they are today
It is not clear to me which post you are responding to since the line you have at the top of your post, "It works slightly differently. The language in the presentation (text, not video) was quite clear*"" does not specify what "It" is nor what presentation you are referring to.
From the rest of your post, I think you may be referring to my reply to the post about the article on the CILAS HELMA-LP system, but I do not see a video or presentation linked in that article. The only link I see is to the CILAS website. There may be a presentation there to which you are referring. In any event, please provide a link to the presentation to which you are referring.
If it is my reply to the post on the CILAS HELMA-LP article to which you are referring, I think you misunderstood part of my reply. Where I wrote "Many current sniper detection and location systems use acoustic sensors to detect the sound of the gun firing and locate the source of that sound, in conjunction with IR sensors that detect and locate the flash from the gun firing. Those systems would not be able to detect nor locate the laser weapon," I was writing about systems that are currently deployed to detect and counter gun-based snipers, not the system that CILAS uses to detect and counter its targets, because my point was that those traditional systems would not be able to detect the CILAS laser based system to counteract it, which is why CILAS would hit the enemy by surprise as the article claimed.
Also, I know how laser illumination sniper detection systems work in conjunction with laser based electro-optic countermeasure systems such as the one you describe since I worked on such systems in the 1990s at the Night Vision and Electronic Sensors Directorate (NVESD), e.g., the Laser Countermeasures System (LCMS), the (Extended) Target Location and Observation System ((E)TLOS), and the High Intensity Targeting System (HITS).
Lastly, acquiring the short pulse train with a staring sensor is not as difficult as you might think. I've done that many times using a high speed photodetector to detect the pulse arrival times to synch a camera's frame shutter (must be a global shutter not a rolling shutter video camera), integration start time and readout start time.
As long as the laser pulse repetition rate is constant, you can trigger the camera on a currently detected laser pulse with a delay time to capture the next pulse in the pulse train. If the laser rep rate is much higher than the camera's highest frame rate, then the camera can be triggered every Nth pulse where N is the ratio of the laser rep rate to the camera's frame rate. One could set the frame integration time on the camera to capture up to N-1 pulses integrated on the camera's focal plane array.
Also, when the short laser pulse is scattered along its path through the atmosphere, what one detects with the photodiode is an elongated pulse from scattering along the beam path through the atmosphere. Even if the incident pulse is only a nanosecond long, the pulse scattered by the atmosphere seen by the photodiode pointed at an air column such that the field-of-view of the photodiode at the laser beam's location was 1 km in length, for example, would be about 3 microseconds long since that is how long the pulse takes to propagate about 1 km.
The staring camera pointed in the same direction as the photodiode with the same FOV as the photodiode and synchronized to the laser pulses would capture a streak of light across its FOV.
The laser sweeping is actually a good thing when the camera is integrating multiple pulses since the amount that the image will smear in the direction of the beam's sweeping from pulse to pulse during the frame integration will be smaller at the edge where the pulses enter the camera FOV than at the edge where they leave the camera's FOV.
If a stationary laser source is within the FOV, it will be at the point of the arc sector formed by the smearing over the pulses as the laser beam scans. If a stationary laser source is outside the FOV, the smear will only be a portion of the arc sector, with the smaller smeared part on the side where the laser source is. The sides of this portion of the arc sector just need to be extended to where they come to a point to determine the laser source location in the direction perpendicular to the camera's optical axis. Of course, in general, without knowing the range to the air columns swept over by the scanning laser, one will need at least 3 cameras looking at the same area from different directions to determine the 3D location of the point in space which their different smeared arc sector projections point. Of course, it will be much harder to locate the laser source if it is moving.