Choose the morphology, choose the number of shells, then give the core and each shell its own optical output. The crystal, host family, rare-earth recipe, combined outside color, magnetic state, and Crystal ID update as you design.
CORE and every enabled shell can have its own excitation gate. Pick UV or IR, then choose the wavelength for that layer. Select a CORE/S1/S2 tab below to make that layer the active design route.
Active layer route: —
WORKED EXAMPLE BELOW · 365 nm UV → Gd₂O₂S:Eu → visible red
Watch an invisible UV input become visible red light.
A simple phosphor story: a 365 nm UV source excites a Gd₂O₂S:Eu crystal. The input photon is not visible to your eye, but Eu³⁺ can release a new photon in the red part of the visible spectrum.
UV INPUT365 nmExcitation energy enters the phosphor.
→
LIVE CRYSTALGd₂O₂S:Eu · Eu³⁺ red outputThe crystal lights up because Eu³⁺ releases visible red emission under the correct UV excitation.
01 · MORPHOLOGY
Choose the crystal form
Morphology is a real design choice for the halide/fluoride route. Other host families are suggested only when the chosen form allows them.
02 · Choose core + shells 0 = core only
RECOMMENDED HOST FAMILY
Fluoride · NaYF₄
Morphology-compatible low-phonon host.
Fe₃O₄ / γ-Fe₂O₃ shell16 nm
Not magneticAdd an iron-oxide layer to make the crystal magnetically addressable.
OFF
04 · CORE + SHELL OUTPUT
Color each layer
Select CORE, S1, S2… then choose that layer’s output. Adding a shell never changes the core.
visible disc · UV hat 240–399 nm · IR hat 780–1700 nm
CORE
#5278EB
Core size250 nm
05 · LIVE CRYSTAL
See your crystal
Each layer keeps its own selected output. The small orb is the predicted combined visible appearance from outside. If a magnetic iron-oxide layer is enabled, the preview shows it as the outermost dark shell.
FINAL OUTSIDE COLOR#5278EBweighted visible combination
COMBINED OUTPUT PREVIEW
#5278EBCore only.
MAGNETIC STATE
Diamagnetic
MAG SIGNAL
0.00 arb.
Iron-oxide layer adds a magnetic handle for separation, tracking, or multifunctional particle design.
IMS CRYSTAL DESIGN NUMBER
initializing…
Dr. Stecher’s current recipe
IMS / NOVAVERA SCHOOL
From patented uniform crystals to optical fingerprints.
Start with the IMS uniform-crystal and multi-excitation interrogation IP, then follow the physics from photons to rare-earth energy levels, timing, power dependence, multi-wavelength excitation, RGB displays, and core/shell architectures.
The Crystal Lab starts with uniform particles and a way to interrogate what is inside them.
At the start of School, the key idea is simple: first make morphologically and size-uniform particles, then probe them optically to learn what they contain. The designer uses those concepts as an educational frame: morphology, composition, excitation wavelength, emission color, rise time, decay time, and power dependence can all help describe a crystal.
The current Advanced Lab shows six excitation channels as a practical educational interface for the multi-excitation interrogation idea described in US11435228B2.
Why use several lasers?
A single wavelength may reveal only one part of a crystal. By stepping through several excitation channels and comparing emission color, intensity, rise/decay behavior, and power response, you can build a richer optical fingerprint of what the particle contains and how its layers communicate.
02 · HOW SIX LASERS IDENTIFY A CRYSTAL
Do not ask only “what color is it?” Ask how the sample responds to six different optical questions.
US11435228B2 describes identifying a photo-responsive material by illuminating it, detecting its emission during and after illumination, measuring how that response changes, and comparing the result with previously measured data. The patent expressly allows a source containing at least five laser diodes. Our Crystal Lab turns that idea into a six-channel teaching model: P1–P6 can be fired sequentially so each wavelength produces its own response trace.
SIX EXCITATION QUESTIONS
P1 365
P2 450
P3 660
P4 808
P5 980
P6 1532
Illustrative wavelengths only. In a real instrument, the laser set is chosen so one or more channels photo-activate the candidate phosphors.
A · RISERecord the first part of the response while the light is turning the material on, before its maximum emission is reached.
B · ON-STATE CHANGEKeep illuminating after the maximum and measure whether the signal stays flat, grows, falls, or changes shape.
C · DECAYTurn the excitation off and record how the emission disappears. That afterglow can be another identifying feature.
A six-wavelength response becomes a fingerprint
Each laser gives a different row of information. A material that looks “green” under one excitation can still be distinguished from another green material because its absorption, emission wavelength, rise, on-state change, decay, and power response are different.
LASERABSORBS?EMISSIONRISEDECAY
P1 · UV
P2 · VIS
P3 · RED
P4 · 808
P5 · 980
P6 · 1532
Bars are explanatory graphics, not measurements from a specific material.
1 · PULSEFire one channelIlluminate the sample with a selected wavelength and controlled power. The patent also describes shaped illumination and extended excitation windows.
2 · WATCHCapture the full traceMeasure emission before the maximum, after the maximum while excitation continues, and after excitation ends.
3 · SPECTRUMRecord emitted wavelengthA detector or detector array determines where the emitted photons appear in UV, visible, or IR.
4 · TIMINGExtract rise + decayHow quickly the signal appears and disappears can separate materials that otherwise emit similar colors.
5 · REPEATAsk five more questionsRepeat with the other laser channels. Some materials respond strongly to only one pump; others reveal additional pathways under several pumps.
6 · MATCHCompare with the libraryThe resulting multi-wavelength pattern can be compared with previously measured fingerprints stored locally or on a remote server.
The identity is the pattern, not one color.A practical fingerprint can combine which excitation wavelengths are absorbed, which emission wavelengths appear, the signal intensity, the rise time, the change while the laser remains on, the decay after the laser turns off, and how those measurements change with input power. Six excitation channels multiply the number of independent observations and make look-alike phosphors much easier to distinguish.
Patent basis · US11435228B2The patent describes interrogation of photo-responsive materials using detected response changes, with optional identification using rise time, decay time, absorbed wavelength, emitted wavelength, comparison with previously measured data, and a light source that may contain at least five laser diodes. The six-channel dashboard shown here is an IMS educational implementation of that broader concept.
03 · PHOTONS + THE ELECTROMAGNETIC SPECTRUM
Light is energy carried in discrete packets.
A photon is a quantum of electromagnetic radiation. It has no rest mass, but it carries energy and momentum. Its wavelength tells you where it falls on the electromagnetic spectrum. Shorter wavelengths correspond to higher photon energy; longer wavelengths correspond to lower photon energy.
E = hc / λ
E is photon energy, h is Planck’s constant, c is the speed of light, and λ is wavelength. For our designer, the important idea is simple: changing wavelength changes the energy available to excite a material.
Gamma
X-ray
UV
VISIBLE
Infrared
Microwave
Radio
short wavelength · higher photon energyhuman vision occupies only a tiny bandlong wavelength · lower photon energy
1 · ARRIVEExcitation photonsA UV, visible, or IR source delivers photons to the crystal.
2 · ABSORBEnergy enters an ionA sensitizer or activator absorbs the photon if an allowed energy pathway exists.
3 · MOVEEnergy transfersEnergy may relax within one ion or migrate between neighboring ions and layers.
4 · EMITA new photon leavesThe emitted photon can be lower, similar, or—through multiphoton processes—higher in energy.
04 · PHOTONS → ELECTRICAL SIGNALS
Your eye is a biological photon detector.
RetinaVisible photons trigger photochemical changes in rods and cones. The retina converts those events into electrical signals that travel through the optic nerve.
The eye does not directly detect UV or IR. It detects visible photons. Rods are very sensitive and dominate dim-light vision. Cones provide color information through three overlapping spectral response bands.
S cone short
M cone medium
L cone long
Rods brightness
So a 365 nm UV photon is invisible to you, but if a phosphor absorbs it and emits a red photon near 615–627 nm, your long-wavelength-sensitive cones can respond strongly. The material has translated invisible excitation into visible information.
05 · RCA / SARNOFF → RGB
The red channel and the display era.
The RCA/Sarnoff research tradition in Princeton was central to the development and commercialization of electronic color television. Color displays combine controlled red, green, and blue light so the eye and brain perceive a broad range of colors.
Europium became one of the important rare-earth routes to a strong red phosphor. Oxide and oxysulfide hosts can support narrow Eu³⁺ red emission, making Eu chemistry a natural teaching example for the “R” channel.
What the user sees on our screenThe incoming UV pump is not rendered as visible light. The crystal output is rendered red because the emitted Eu photon is in the visible red band.
06 · HOW RARE-EARTHS WORK
Shielded 4f states act like an internal optical engine.
Lanthanide ions are unusual because the optically important 4f electrons sit inside more external filled orbitals. Those outer electrons partially shield the 4f states from the surrounding crystal. As a result, many rare-earth ions retain sharp, recognizable optical transitions even when the host material changes.
SENSITIZERCollects excitationYb³⁺ and Nd³⁺ are common examples. They absorb efficiently at selected pump wavelengths and pass energy onward.
ACTIVATORSets the outputEr³⁺, Tm³⁺, Ho³⁺, Eu³⁺, Tb³⁺ and Pr³⁺ can define visible or IR emission lines.
HOSTBuilds the environmentNaYF₄, GGG/GGAG, oxides and oxysulfides determine phonon losses, ion spacing, crystal field, morphology, and energy-transfer efficiency.
07 · RISE + DECAY TIME
Two crystals can emit the same color and still have different clocks.
Rise time is how quickly emission builds after excitation starts. Decay time is how quickly emission falls after the excitation is removed. These values can range from very fast to microseconds or milliseconds depending on ion, host, energy-transfer path, particle architecture, concentration, surface loss, and measurement conditions.
RiseTracks how quickly population reaches the emitting state. Multi-step energy transfer often makes the rise slower than direct excitation.
DecayTracks how quickly excited-state population disappears. It is a useful optical fingerprint because different particles can have measurably different lifetimes.
Why IMS cares about timingIn the multi-excitation interrogation approach represented here, timing helps distinguish particles beyond simple color alone. Rise and decay behavior can become part of the optical fingerprint when paired with wavelength and power-dependent response.
08 · POWER DEPENDENCE
Brightness—and sometimes color balance—depends on how hard you drive the crystal.
In upconversion especially, emission is often nonlinear with excitation power. As the pump becomes stronger, additional multiphoton pathways can become populated. That can change total brightness and the relative intensity of green, red, blue, UV, or IR lines.
Power dependence is therefore not merely a brightness slider—it can be part of the material’s identity. The pending IMS authentication disclosure specifically describes excitation-power-dependent spectral profiles and peak ratios as information-bearing properties.
09 · MULTIPLE WAVELENGTHS
Some optical pathways need a sequence, not a single color of light.
Certain coupled rare-earth systems can require—or strongly benefit from—more than one excitation wavelength. A first wavelength can populate an intermediate level or sensitizer; a second wavelength can then promote the system into another state or open a different transfer route. The exact behavior depends on host, dopants, concentration, pulse timing, and architecture.
STEP 1First excitationPopulate a sensitizer or intermediate Pr³⁺-containing pathway.
→
INTERMEDIATEStore / transfer energyEnergy waits, migrates, or reaches a second ion or manifold.
→
STEP 2Second wavelengthA second photon can unlock another transition or optical conversion.
Pr example—use carefullyPr³⁺ has many accessible manifolds and appears in multi-ion downconversion/quantum-cutting research. Not every Pr phosphor requires two excitation wavelengths, but multi-step Pr-based architectures are a useful illustration of why sequential or multi-wavelength interrogation can reveal behavior that a single pump misses. The pending IMS disclosure explicitly notes that a crystal may be interrogated first by one wavelength and then by a second to cause an optical conversion.
10 · THREE WAYS TO CHANGE LIGHT
Upconversion, downshifting, and quantum cutting are different pathways.
IR + IR → VIS
UpconversionTwo or more lower-energy excitations are accumulated before a higher-energy photon is emitted. NaYF₄:Yb/Er or NaYF₄:Yb/Tm are classic design spaces.
UV → RED
DownshiftingOne higher-energy photon is absorbed and a lower-energy photon is emitted after non-radiative relaxation. Gd₂O₂S:Eu under UV is a clean example.
UV → NIR + NIR
Quantum cuttingOne high-energy excitation can, in suitable coupled systems, produce two lower-energy excitations or photons. Pr/Yb garnet systems are an important research route.
11 · WHY CORE + SHELLS MATTER
Architecture controls where energy is absorbed, transferred, protected, and emitted.
OUTER SHELL surface / magnetic / protection
SHELL transfer / isolation
CORE sensitizer + activator
A crystal is not just a chemical formula. Its architecture can separate ions that would otherwise quench each other, move energy across an interface, protect emitters from surface losses, or add a second function such as an iron-oxide magnetic layer.
Inert shell: passivates the surface and suppresses non-radiative loss.
Active shell: adds another sensitizer or emitter pathway.
Energy-migration layer: lets excitation move before reaching the final activator.
Magnetic outer layer: adds a manipulable magnetic handle while keeping optical layers inside.
12 · WORKED EXAMPLE
365 nm UV → Gd₂O₂S:Eu → red
A near-UV photon is absorbed by the phosphor system. Energy reaches Eu³⁺ excited states, then Eu³⁺ relaxes radiatively and releases red photons. The incoming and outgoing photons are different wavelengths because some energy is lost to the material before emission.
EXCITATION365 nm UVinvisible pump
→
PHOSPHORGd₂O₂S:Eu
host + Eu³⁺ activator
→
EMISSIONEu³⁺ redvisible output near the red Eu manifold
What would the material look like?With the UV excitation off, a powder or coating may look pale, white, or lightly colored depending on composition and particle scattering. Under the correct UV excitation, the emitted red light can dominate its visual appearance.
13 · FULL EDUCATIONAL DIEKE-STYLE MAP
Read the vertical axis as stored electronic energy.
The classic Dieke-diagram idea places rare-earth energy manifolds side by side so you can see which transitions and energy-transfer steps are plausible. Lines higher on the chart represent higher-energy electronic states. An excitation arrow moves energy upward; an emission arrow drops to a lower state and releases a photon.
energy manifoldpump / absorptionemissionCe · Pr · Nd · Sm · Eu · Tb · Dy · Ho · Er · Tm · Yb
Educational Dieke-style map for design intuition. It is not a substitute for a transition-resolved spectroscopy table: exact manifold energies, Stark splitting, branching ratios, lifetimes, and host-dependent shifts should come from the linked papers and databases.
14 · DESIGN EXAMPLES
Different excitation/output pairs lead to different phosphor families.
UV → REDGd₂O₂S:EuDirect/downshifted Eu red emission; strong teaching example for display phosphors.
980 IR → GREEN / REDNaYF₄:Yb,ErLow-phonon fluoride host; Yb sensitization feeds Er visible upconversion.
980 IR → BLUE / VIOLETNaYF₄:Yb,TmYb/Tm routes access blue, violet, UV, red, and NIR manifolds depending on concentration and architecture.
UV / VISIBLE → NIRGGG / GGAG + Pr/Yb/NdGarnet families provide useful downconversion, sensitizer-transfer, and quantum-cutting research space.
15 · A SHORT MATERIALS HISTORY
From glowing powders to engineered nanocrystals.
Early phosphorsMinerals and inorganic powders established that absorbed energy could be stored and re-emitted as visible light.
CRT / display eraRed, green, and blue phosphors became engineered components of electronic displays and color television.
Rare-earth phosphorsEu, Tb and other lanthanides brought sharp, chemically tunable emission lines and improved color purity.
Nanocrystal eraControlled particle size, morphology, doping, and core/shell growth made energy flow an architectural design variable.
IMS / NovaVeraThe designer treats excitation, host, rare-earth recipe, morphology, shells, timing, and magnetic functionality as one integrated material system.
P1–P6 wavelength and power density (W/mm²). Active pumps gate the modeled rare-earth route.
Nearest literature anchor: 980 nm
2 · DESIRED OUTPUT
Choose the target
Visible output is selected in the disc. UV and IR are chosen directly on the spectral hats — no sliders.
SELECTED OUTPUT WAVELENGTH475.0 nm · visibleModeled dominant wavelength for the selected output.
MODEL READY
click / drag either spectral hat
TARGETTarget #5278EB
MODELED OUTPUTProduced —
Modeled recipe: —
PHOSPHOR ROUTE—
HOST—
RECIPE—
RESPONSE—
Solver waiting for excitation + target.
—
3 · OPTICAL SPECTRUM
UV + Visible + IR
Transition positions stay fixed; modeled intensities change with excitation, recipe, power and target.
Contributors: —
4 · INPUT CONDITIONS
Laser timing + power
CW excitation · duty cycle 100%
5 · MATERIALS + LAYERS
Host + rare-earth route
ACTIVE LAYER RECIPE
—
—
Thickness: 16 nm · magnetic layer sits outside the optical shells.
6 · KINETICS + MAGNETICS
Combined response
KINETIC SIGNATURE—
RISE COMPONENT—
DECAY COMPONENT—
Arbitrary combined number derived from modeled rise and decay behavior — useful as a design fingerprint, not a measured lifetime.
Magnetometer0.00 arb.
7 · PARTICLE + ARCHITECTURE
Geometry
8 · DESIGN STATE
Current crystal
IMS CRYSTAL DESIGN NUMBER
—
—
COMBINED OUTSIDE COLOR
—
9 · MODEL NOTES
Evidence state
Paper-guided excitation and emission anchors. Exact concentration, shell and lifetime values remain modeled unless a cited experiment matches the selected design.
10 · DATABASE SOURCES + TRANSITION RECORDS
Phosphor / spectroscopy databases
Curated database records sit beside the paper engine. Matching records light up and can also appear as small DB anchors on the optical spectrum. The CSIRO records below are a curated snapshot, not a live API feed.
All papers remain visible. The literature engine lights up the papers that best match the current excitation, target wavelength, host, ions, shells, and morphology.
