NIST scientists create 'any wavelength' lasers
NIST researchers have demonstrated chip-scale devices that can generate many discrete laser wavelengths across a wide range of the spectrum, potentially freeing designers from today’s narrow set of economical laser colors. Commenters see promising applications in fiber-optic and on-chip communications, quantum and ion-trap computing, precision spectroscopy, displays, and materials processing, while noting constraints such as fiber transparency windows, power requirements, safety implications, and the fact that these are selectable rather than continuously tunable wavelengths. Alongside the technical implications, the thread veers into how humans perceive color, highlighting that many familiar colors (like magenta and brown) are not single wavelengths at all but constructs of our visual system.
Scope and Capabilities of the Device
- Some argue this is mostly about integrated optics that manipulate frequency via nonlinear effects, not a fundamentally new tunable diode laser.
- Others counter that it effectively functions as a chip-scale “supercontinuum source,” approximating “any wavelength” output.
- A key clarification: devices produce many discrete, design-time-selectable wavelengths, not a smoothly tunable, arbitrary frequency dial. Fine thermal tuning is limited.
- Reported efficiency example cited from the paper: ~35 mW in, ~6 mW out at 485 nm.
Relevance to Photonic and Quantum Computing
- Several comments say “photonic computing” hype is overstated: photonic switches (e.g., interferometers) are physically larger and likely more expensive than CMOS, so not a general-compute replacement.
- Stronger case is made for:
- Low‑power, high‑bandwidth optical interconnects.
- Quantum computing with ions or neutral atoms, where arbitrary wavelengths remove constraints on which species can be used and enable access to specific atomic transitions and Rydberg states.
- One detailed view: photonics is great for communication and interferometric processing, but bulk CMOS still wins for logic density and cost.
Communications and Bandwidth
- Potential to pack more distinct colors into fiber for wavelength-division multiplexing is discussed, but several note:
- Fiber has limited low‑loss windows; visible wavelengths attenuate too strongly for long-haul use.
- Current telecom tech already densely populates these windows.
- Distinction made between: photons vs electrons speed; information in electronics already propagates near light speed, so benefits are mainly bandwidth, not latency.
Other Applications and Limitations
- Suggested uses:
- Precision spectroscopy and chemistry by matching molecular/atomic transitions.
- Tailored industrial lasers for cutting, welding, drilling, and possibly rock tunneling or geothermal boring.
- Quantum sensing and metrology.
- EUV/gamma/microwave variants are considered unlikely with this approach; EUV in particular is heavily absorbed and hard to handle at high power.
Color, Displays, and Perception
- Extensive side discussion on:
- Non-spectral colors (magenta, brown), CIE color space, and “impossible colors.”
- Idea that two tunable lasers could, in principle, reproduce any perceivable color and represent the “final frontier” of display tech.
- How language, context, and physiology shape color perception; debates on whether naming colors changes what we can perceptually distinguish.
Safety, Weapons, and Practical Concerns
- Concern raised that arbitrary-wavelength sources could defeat laser safety goggles that rely on narrow-band blocking.
- Speculation about weaponization (e.g., bypassing wavelength-specific protections), but details remain unclear.