Expert ROMSHI talks about lasers

Why 23–25 °C is the Ideal Temperature for a Diode Stack in Hair Removal Lasers?

Why 23–25 °C is the Ideal Temperature for a Diode Stack in Hair Removal LasersIn the world of professional cosmetology, the longevity of equipment is one of the key factors for a salon's success. The diode stack in the 808 nm laser handpiece is the "heart" of the device, and its lifespan directly depends on operating conditions. Manufacturers (including Romshi) recommend maintaining the cooling water temperature in the range of 23–25 °C. Why exactly this range, and not lower or higher? Let's break it down point by point.
  1. Maximum Energy Conversion Efficiency
    Diode lasers based on AlGaAs/InGaAs reach peak efficiency precisely at 23–25 °C.
  • Minimal heat losses.
  • Most of the energy is converted into useful radiation.
Every +10 °C above the optimal temperature reduces efficiency by 3–5% and increases the threshold current. Result: more electricity consumed for the same flash power.
  1. Stable Wavelength — 808 nm
    The diode's wavelength shifts by approximately 0.3 nm per degree.
  • At 25 °C: precise 808 nm, perfectly absorbed by melanin in the hair follicle.
  • At 35 °C: already 811–812 nm — poorer melanin absorption, more skin heating, lower procedure efficiency and safety.
Stable wavelength = predictable results and happy clients.
  1. Maximum Stack Lifespan
    High temperature is the main enemy of diode longevity.
  • At 23–25 °C, a quality stack delivers 10–30 million flashes.
  • At 35–40 °C, lifespan can drop 2–3 times due to accelerated degradation (CAT and gradual degradation).
Fewer replacements = higher profits.
  1. Reliable Power Stability
    The cooling system (TEC Peltier + water) operates most accurately and efficiently in the 23–25 °C range.
  • Below 20 °C: risk of condensation, corrosion, and short circuits.
  • Above 30 °C: sharp drop in power and overheating.
Why not lower, like 15 °C?
Lower temperatures provide a slight efficiency boost, but:
  • Require a much more powerful cooling system.
  • Increase energy consumption.
  • Raise the risk of condensation.
  • Make the handpiece more expensive and bulkier.
23–25 °C is the golden mean: maximum efficiency, stability, and lifespan at reasonable costs.Conclusion
By maintaining water temperature at 23–25 °C, you get:
  • Precise 808 nm wavelength.
  • Millions of safe and effective flashes.
  • Minimal maintenance and replacement costs.
  • Consistent results and loyal clients.
At Romshi, we produce 808 nm diode stacks designed specifically for this optimal mode — so your equipment works for years without losing power.Need quality stacks or spare parts?
www.romshi.com | +79180110234
Worldwide shipping from China.