The Decline of Halogen Light Sources And what comes next for industrial spectral inspection

For decades, halogen lamps have been a workhorse in industrial spectral inspection setups. They offer wideband emission, a relatively smooth spectrum, and an attractive price point. But the landscape is rapidly changing.

Across Europe and many other regions, halogen lamps have already been phased out in the consumer market due to stricter energy-efficiency rules. While industrial and scientific applications still enjoy certain exemptions, the direction is clear: halogen is becoming increasingly difficult to source, maintain, and justify, both technically and economically.

Industry analysts leave no doubt:

Why is halogen disappearing?

1.     Regulations are tightening

EU Ecodesign rules have effectively banned most halogen lamps for general lighting since 2018–2021. Although industrial lamps are not outright prohibited, they are subject to the same energy-efficiency pressure and material restrictions. Each update of these directives narrows the exemptions further. The future no longer looks bright for halogen and reconsidering alternatives is imminent.

2.     Manufacturers are scaling down production

As demand collapses in the consumer market and LEDs dominate general lighting, halogen production lines are being discontinued or repurposed. For OEMs, this creates three structural uncertainties:

• Supply risk: as fewer manufacturers remain, production runs become irregular, and lead times increase, making long-term availability difficult to guarantee

• Rising prices: as volumes decline and competitive pressure disappears, removing the economies of scale that historically kept halogen cost-effective

• Long-term system maintenance uncertainty because replacement lamps or compatible variants, and qualified suppliers may no longer be available over the lifetime of an installed system, complicating service contracts and lifecycle planning
  

3.     Halogen’s technical limitations are no longer acceptable

For domains that once depended on halogen, like spectroscopy and industrial spectral inspection, the drawbacks are becoming evident:

• Low brightness means long integration times – as fewer photons reach the detector per unit time, the system must integrate longer to achieve sufficient signal-to-noise ratio

• High heat load adds complexity and cost to the system as additional thermal management is required, driving more complex designs and higher component and integration costs

• Short lifetime and aging effects require frequent replacement

• Instability impacts repeatability and throughput
  

In an era of faster production lines, higher-resolution sensors, and 24/7 uptime expectations, these constraints are no longer workable and a better alternative is required for future-proofing new applications.

A better future for industrial spectral inspection illumination

As halogen fades, system manufacturers and industrial inspection companies face a critical question: What replaces it? SLEDs or supercontinuum lasers?

LEDs falling short of the promise

LEDs are compact and scalable but constrained to narrow ranges. LEDs typically cover 20–50 nm of bandwidth. Many spectral inspection techniques require hundreds of nanometers of continuous spectrum to capture multiple absorption features at once. Achieving this with LEDs requires stacking multiple sources, increasing optical complexity, alignment effort, and cost, while still leaving spectral gaps. LEDs deliver orders-of-magnitude lower brightness per nm, which translates to longer integration times, lower throughput and reduced sensitivity. Whilst halogens already suffer from this limitation, LEDs only partially improve it.

In short, LEDs are a stopgap solution: better than halogen in efficiency, but still fundamentally limited for industrial spectral inspection.

Legacy supercontinuum lasers: a poor alternative

Traditional supercontinuum light sources or broadband lasers outclass the brightness of halogen and LEDs.  Their higher photon flux. As it focuses more light on the sample, it can work at larger standoff distances and can be efficiently coupled into fiber, enabling better throughput. These benefits make traditional supercontinuum lasers a good fit for inline industrial spectral inspection, however, they come with significant drawbacks:

• High noise levels and spectral instability from pulse to pulse requires averaging over many pulses

• Bulky, heavy form factor, unsuitable for inline integration

• Long startup times, frequent calibration, and ongoing maintenance

• Laser Safety Class 4 — restricting use in industrial and medical environments

This is exactly where SuperLight Photonics offers a breakthrough.

SuperLight Photonics’ PIC-based wideband laser light source: The next-gen halogen alternative

SuperLight Photonics’ patented supercontinuum technology delivers a wideband light source with the reliability and scalability of a PIC (Photonics IC) solution. It doesn’t just replace halogen, it outperforms it on every key parameter that matters in spectral inspection systems:

1. High brightness

High brightness enables shorter integration times and higher throughput, making it ideal for inline industrial spectral inspection.

2. Wide, low-noise spectral output

A smooth, stable spectrum ensures excellent axial resolution and repeatability.

3. Ultra-stable and maintenance-free

No thinning tungsten filaments, no heat-driven degradation, no warm-up behavior. Just consistent performance, day after day.

4. Compact, efficient, and scalable

Built on a PIC platform, SuperLight Photonics’ light source reduces power consumption, eliminates bulky optics, and fits into OEM modules with ease. Supply is predictable and scalable and there is no dependency on a sunset lamp industry.

5. Class III laser safety simplifies industrial deployment

Class IIIb laser safety significantly reduces the need for extensive laser safety precautions. Its operation avoids the need for enclosed beam paths or laser safety interlocks, reducing system complexity, space requirements, and certification effort to enable inline while eliminating the need for specialized laser training or additional safety precautions for operators.

6. Industry-ready performance

Designed with industrial spectral inspection requirements in mind: spectral stability, wideband coverage, high dynamic range, and the temporal coherence needed for precise depth measurements.

The transition is inevitable

For years, the challenge was finding a wideband alternative to halogen lamps that matched its simplicity and spectral quality while delivering modern performance. That alternative has arrived.

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