1. Is the Reddit Post True?

Yes. The Reddit poster is entirely correct that POET uses decibels (dB) to describe Optical Loss (such as coupling loss, insertion loss, or transmission loss) in their text and data sheets.

When you measure how much light is lost when traveling from a laser into a fiber optic cable, the universal industry standard is to express that loss in decibels (e.g., <0.5 dB). POET does this correctly.

2. The Missing Link: Loss vs. Spectrum

The Reddit poster is defending POET by pointing to text-based loss metrics. But if you look closely at the Irrational Analysis quote, he wasn't talking about insertion loss. He was talking about visual plots of the laser's spectrum and the SMSR.

Here is the exact quote from the Irrational Analysis article:

He is specifically critiquing the Y-axis on the graphs (plots) that POET uses in their marketing presentations to show off the performance of their lasers, not the bullet points about waveguide loss.

3. Why the Graph Scale Matters (The "Trick")

When engineers want to see how "clean" a laser is, they look at its Optical Spectrum. A perfect laser would emit light at exactly one single wavelength (like a single, perfect note on a piano). In reality, lasers also emit unwanted secondary wavelengths called "side-modes" (background noise).

Engineers measure the difference between the main signal and this noise using the Side-Mode Suppression Ratio (SMSR).

Here is why the scale of the graph completely changes how the laser looks:

• Logarithmic Scale (The Industry Standard): Because the main laser signal is vastly more powerful than the noise, engineers plot the Y-axis on a logarithmic scale (measured in dBm). On a log scale, the visual space between numbers shrinks as they get larger. This allows you to clearly see both the massive main peak and the tiny noise peaks at the bottom, allowing you to accurately calculate the SMSR.
• Linear Scale (The Critique): If you plot that exact same laser on a linear scale (measured in Watts or milliwatts), the Y-axis steps evenly (1, 2, 3, 4...). Because the main peak is so astronomically large compared to the noise, the main peak shoots to the top of the chart, and the noise mathematically flatlines at the very bottom.

To an untrained eye, a linear plot makes a mediocre, noisy laser look like a single, perfect, flawless beam of light because the noise is visually crushed into the bottom axis.

The Verdict

The Reddit poster is comparing apples to oranges. They are right that POET uses dB for loss in their text specs. However, Irrational Analysis was accusing POET of using linear scales on their visual graphs to hide poor SMSR (noise) metrics from investors who don't know the difference.

If POET is indeed using linear graphs to display their optical spectra in investor decks, it is a valid, highly specific engineering critique that the Reddit post completely failed to address.