405 nm Laser Module

Where 405 nm lasers are used

405 nm sits at the short end of what diode lasers deliver at useful power, and that makes it the workhorse of violet excitation. Two very different fields use it: fluorescence, where it matches a whole class of markers, and photochemistry, where the photon energy itself does the work.

• Fluorescence microscopy and cytometry. The standard line for DAPI, Hoechst and the Alexa Fluor 405 family.
• Raman spectroscopy. The highest scattering cross section of the common excitation lines, with additional resonance enhancement for species that absorb in the violet. Usable on inorganics and minerals that do not fluoresce.
• Curing and adhesive processing. Initiator systems formulated for the 395 to 405 nm range.
• Stereolithography and direct imaging. Resin systems designed for violet exposure.
• Forensics and anti-counterfeiting. Many security features fluoresce under violet excitation.

If your marker is CFP, 405 nm is not the best match. Its excitation peak sits closer to 440 nm, and our 445 nm modules will give you considerably more signal for the same optical power.

405 nm or 375 nm?

405 nm is the practical choice when you need violet at real power. Our 405 nm modules reach 1000 mW in multimode versions, while 375 nm tops out considerably lower. If your fluorophore is DAPI or Hoechst, 375 nm sits closer to the absorption peak but costs you both power and budget, so most instruments use 405 nm on the shoulder of the band and accept the efficiency loss.

See the 375 nm laser when the shorter line is genuinely required, or the 532 nm laser module if you are choosing an excitation line for Raman rather than fluorescence.