LASERS

    325 nm HeCd laser replacement: What can replace Kimmon's discontinued helium cadmium lasers?

    26 October 2026

    Kimmon Koha has announced that it will discontinue helium-cadmium (HeCd) laser production by the end of December 2026.

    For existing users, the immediate concern is continuity. However, replacing a HeCd laser also presents an opportunity to reconsider the limitations of this legacy technology and assess modern alternatives.

    When will Kimmon stop manufacturing HeCd lasers?

    In its October 2026 announcement, Kimmon Koha confirmed that it will exit the HeCd laser business and close its Fukushima factory by 31 December 2026.

    The manufacturer has published the following deadlines - depending on stock and component availability:

    • 16 November 2026: Final order date for standard catalogue products and laser-tube replacement services.
    • 27 November 2026: Deadline for replacement products to arrive at the Fukushima factory for tube replacement.
    • 18 December 2026: Final order date for specified remaining models, IK3201R-F and IK3501R-G, subject to stock availability.
    • 31 December 2026: Closure of HeCd laser operations and the Fukushima factory.
    • 31 December 2028: Intended end of maintenance and repair support, provided parts and service capabilities remain available.

    What does Kimmon's discontinuation mean for existing HeCd users?

    In October 2026, Kimmon announced that it would withdraw from HeCd laser manufacturing and close its Fukushima factory by 31 December 2026. The company cited difficulties sourcing cadmium and other materials, alongside declining demand associated with increasingly restrictive RoHS regulations.

    Orders for standard products and tube replacements will close on 16 November 2026, with limited additional availability for specified models until 18 December. Kimmon intends to provide maintenance and repair support where feasible until December 2028, subject to parts availability.

    The announcement makes long-term laser availability an important consideration for labs and manufacturers, particularly where a system nearing end-of-life could interrupt established production or ongoing experiments.

    What can replace a 325 nm HeCd laser?

    Diode-pumped solid-state (DPSS) lasers offer an alternative to gas laser technology, with critical differences in both optical performance and day-to-day operation.

    HeCd lasers rely on high-voltage gas-discharge tubes that consume electrical power, generate waste heat, and require frequent servicing or replacement. The transition to solid-state technology removes the HeCd tube and its associated maintenance requirements, while reducing dependence on cadmium-containing components.

    The Skylark 320 operates at 320 nm, delivering up to 200 mW of continuous-wave, single frequency UV output. The solid-state architecture combines efficient operation, with high output power, narrow linewidth, low noise, and excellent beam quality.

    This provides substantially more available power than HeCd systems, which Kimmon lists at outputs of up to 50 mW, as well as other available DPSS systems on the market which currently offer up to 40 mW.

    Beyond higher output power, the Skylark 320 provides greater power headroom, allowing for more flexibility in system design. Clean, single frequency output and excellent beam quality also reduces the need for additional mode filtering and beam-cleaning optics, simplifying integration without compromising optical performance.

    Skylark 320 DPSS lasers vs. 325 nm HeCd lasers

    The Skylark 320 combines higher output power with narrow linewidth, excellent beam quality, and significantly lower electrical consumption than 325 nm HeCd systems. The comparison below highlights the key technical and operational differences:

    Skylark 320 DPSS laser HeCd 325nm laser
    Wavelength 320 nm 325 nm
    Output power 200 mW 50 mW
    Linewidth 0.0005 GHz (<500 kHz) 1.0 GHz
    Beam pointing stability ≀ 5 ΞΌrad/Β°C ≀ 25 ΞΌrad/Β°C
    Power noise 0.3% RMS 4.0% RMS
    Coherence length > 100 m 0.3 m
    Wall plug efficiency 0.35 % 0.007%
    Power draw 50 W 700 W

    Which applications benefit from replacing HeCd lasers with 320 nm DPSS systems?

    The Skylark 320 DPSS lasers replaces 325 nm HeCd lasers in applications where the 5 nm wavelength difference is acceptable, particularly in optical grating manufacturing, interference lithography, semiconductor photoluminescence and UV Raman spectroscopy.

    For holography and interference lithography, 200 mW output power, MΒ² ≀1.1, and coherence length exceeding 100 m provides power headroom and a reduced need for spatial mode filtering. Skylark Lasers' optical grating manufacturing customers report eliminating additional mode filtering and achieving over 92% grating transmission efficiency, compared with 70% when using HeCd lasers.

    In semiconductor photoluminescence, 320 nm excitation provides a higher photon energy than 325 nm, improving excitation of wide-bandgap semiconductor alloys and heterostructures with absorption thresholds near 3.8 – 3.9 eV. For suitable semiconductor structures, the combination of 320 nm excitation, stable output and available power provides flexibility when designing or upgrading PL setups.

    For UV Raman spectroscopy, the Skylark 320 provides narrow linewidth and single frequency excitation.

    The key replacement criteria are wavelength compatibility, required output power, beam geometry, and spectral performance. Applications with a strict 325 nm wavelength requirement, wavelength-sensitive components that cannot be changed, or a low output power requirement are not direct candidates for the Skylark 320.

    β€œAn excellent replacement for a HeCd laser: emission is spectrally pure, efficiency is much better, it provides better longevity with cheaper maintenance, and it is much smaller.”

    SEMICONDUCTOR INSPECTION CUSTOMER

    β€œIt’s taken 15 years to find a suitable replacement for our HeCd laser. The clean mode enables us to manufacture high fidelity gratings with > 92% transmission efficiency (vs. 70% with HeCd)”

    OPTICAL GRATING MANUFACTURER

    β€œThe Skylark 320 laser is an excellent, efficient source for laser interference lithography [techniques], a great improvement over gas systems, and with spectrally clean emission.”

    SEMICONDUCTOR MATERIALS ANALYST

    β€œThe Skylark 320 DPSS laser remained stable at maximum power for over 20 days (the length of the measurement). Stable and uniform exposure was achieved in the inspection set up, which requires extremely stable UV light.”

    CONSUMER ELECTRONICS MANUFACTURER

    Plan for the end of your HeCd laser’s service life

    With Kimmon discontinuing HeCd production, now is the time to evaluate a solid-state alternative. Contact Skylark Lasers with your existing HeCd model, application, and power requirements to assess 320 nm compatibility and identify a suitable replacement path.