Skip to content In this 32-part series, Russ Sadler takes a deep experimental look at blue diode laser technology. Rather than reviewing brands or providing generic settings, the series investigates how 455 nm diode lasers generate, focus and deliver energy, how different materials respond, and why apparently simple ideas such as spot size, power percentage and focus can be more complicated in practice.
The series develops progressively from the behaviour of a single 5 W diode through 10 W, 20 W and 40 W heads, then moves into image engraving, cutting, air assist, material response, colour effects and the practical limits of diode systems.
Diode Lasers – Under the Hood Series
- 01 – How Diode Lasers Interact with Materials
- 02 – Wavelength, Beam Profiles and Laser Light
- 03 – Lenses, Focus and Beam Expansion
- 04 – First Practical Diode Tests: Engraving and Timing
- 05 – Inside a 5 W Diode Laser Head
- 06 – Acrylic Engraving with a 5 W Diode Laser
- 07 – How Blue Diode Light Interacts with Acrylic
- 08 – Measuring Power, PWM and What Controls the Burn
- 09 – Material Test Matrices: Speed, Power and Wood Colour
- 10 – Engraving Wood: Line Interval, Focus and Surface Damage
- 11 – Digital Images: Pixels, PPI, Dithering and Resolution
- 12 – Photo Engraving in Practice with a 5 W Diode
- 13 – Text Engraving on Wood: Contrast and Durability
- 14 – Moving from 5 W to 10 W: Optics and Lens Orientation
- 15 – The 10 W Beam: Focus, Two Diodes and Beam Intersection
- 16 – Cutting with a 10 W Diode: What Happens Away from Focus
- 17 – Greyscale, Anodised Aluminium and the 10 W Beam
- 18 – Moving to 20 W: Beam Shape, Focus and Metal Marking
- 19 – 20 W Cutting and the Effect of Air Assist
- 20 – Why Air Assist Changes the Cut
- 21 – Which Materials Can a 455 nm Diode Laser Cut?
- 22 – Metal Colour Marking and 20 W Power Stability
- 23 – 3D Engraving with a 20 W Diode Laser
- 24 – Moving to 40 W: Motion, Weight and Acceleration
- 25 – Inside a 40 W Diode Head: Spot Size and Marketing Claims
- 26 – What a Diode Laser Is Actually Good At
- 27 – Why Wood Needs Carbon to Absorb Blue Light
- 28 – How Diode Laser Cutting Actually Works
- 29 – 40 W Beam Behaviour, Spot Size and Output Variation
- 30 – Colour Marking Stainless Steel: Interference, Not Paint
- 31 – Photo Engraving on Tiles: Titanium Dioxide and the Norton Process
- 32 – Final Tests and Conclusions: Glass, Slate and What Comes Next
These pages are concise overviews of the original videos. They are designed to help you understand the subject and find the relevant session quickly, while the original video remains the primary source for Russ’s demonstrations and experiments.
For a consolidated engineering explanation organised by subject rather than episode order, see the Diode Lasers Explained: Under the Hood technical guide.
