This video provides an in-depth review, demonstration, and teardown of the ComMarker Omni 1, a 5-watt, 355nm pulsed UV laser engraver. The presenter explores its unique capabilities, contrasting it with more common infrared lasers by showcasing its superior performance on a wide range of materials, including plastics, wood, textiles, glass, and highly reflective metals like copper. The laser's strength lies in "cool ablation," a photochemical process that allows for clean, precise markings with minimal thermal damage. Key applications demonstrated include high-resolution PCB prototyping, silicon wafer dicing, and, most notably, sub-surface engraving inside solid glass blocks.
The video documents an advanced experiment to create 3D models suspended in glass, detailing the technical hurdles such as motorizing the Z-axis, using open-source control software, and compensating for the material's refractive index. The final teardown reveals a complex Diode-Pumped Solid-State (DPSS) laser source that uses two stages of harmonic generation to convert an 808nm infrared diode's output to the final 355nm UV wavelength. The presenter theorizes that thermal lensing in the optical crystals is the cause of beam shape distortions observed with different pulse settings.
The ComMarker Omni 1: A Deep Dive into UV Laser Capabilities
0:00:18 Introduction to the UV Laser: The video reviews the ComMarker Omni 1, a 5-watt, 355nm pulsed UV laser. Unlike infrared lasers that rely on heat, this machine uses a "cold" photochemical process, making it uniquely versatile.
0:03:25 Dual Lenses and Spot Size: The machine includes two lenses for different working areas (70x70mm and 150x150mm). The smallest achievable spot size was measured at 40 micrometers, with the key finding that pulse timing parameters (e.g., 30 kHz, 12 ns) critically affect the beam's focus and shape.
0:06:32 The Advantage of "Cool Ablation": The UV laser excels where infrared lasers struggle. It can mark materials by directly severing chemical bonds, resulting in clean cuts and engravings on plastics, wood, and textiles with minimal charring, melting, or discoloration.
0:11:37 Universal Material Marking: The laser demonstrates remarkable compatibility with nearly any material. It can easily mark highly reflective metals like copper and transparent materials like glass, both of which are challenging for infrared lasers.
0:15:54 Sub-surface Glass Engraving: A standout feature is the ability to focus the beam inside a solid block of glass to create internal markings without affecting the surface. This opens up possibilities for creating microfluidic devices, decorative 3D models, and other complex structures.
0:17:15 High-Resolution PCB Prototyping: The laser proves to be an exceptional tool for creating custom PCBs. It cleanly removes the copper layer from FR4 substrate without burning or damaging it, enabling the fabrication of circuits with extremely fine features and tight clearances (down to 80 micrometers).
0:22:25 Experimental 3D Printing in Glass: The presenter undertakes an advanced project to create 3D models inside a glass cube. This required motorizing the Z-axis and using open-source software ("Balor") for control, highlighting challenges like compensating for the glass's refractive index and managing heat to prevent cracking.
0:29:44 Laser Source Teardown: The teardown reveals a sophisticated Diode-Pumped Solid-State (DPSS) system. It begins with an 808nm infrared pump diode, then uses a sequence of non-linear crystals for second-harmonic generation (to 532nm green light) and third-harmonic generation (to the final 355nm UV light).
0:35:44 Understanding Beam Distortion: The presenter hypothesizes that "thermal lensing" causes the beam shape to degrade with certain settings. Because the pump power is constant, different pulse rates create varying heat loads within the optical crystals, distorting their refractive properties and thus the laser beam itself.