Laser beam renders with unexpected dark band at view center

[aomanchuria]

.blend file: ray_tracing.zip

Steps to reproduce: Create new file with camera and light. Change render engine to Luxcore, set light to laser with default power 100W, 17L/W 0.1 to 1m width. Add world volume, change to homogeneous volume with scattering scale ~ 0.7.

Screenshots or rendered images:

Error message from Blender console: no errors.

OS: Windows 10 Blender version: 3.1.2 LuxCore version: 2.61

[aomanchuria]

I've added a few more examples by adding subsequent mirrors. you'll notice how the beam seems to fade in certain locations right after every bounce ray_tracing.zip .

[odil24]

I can confirm this as bug!