Packaging Choices That Matter for 895nm 1mW VCSELs: TO-Can vs SMD vs Non-Magnetic
895nm 1mW VCSELs hit a sweet spot for eye-safety, silicon-detector response, and compact optics in short-range sensing.
TO-Can = rugged, hermetic, easy heatsinking; great for labs, pilot runs, and harsh environments.
SMD = low Z-height, SMT throughput, tight module integration; watch reflow profiles and window films.
Non-magnetic = nickel-free, ceramic/glass stacks for quantum sensors (e.g., Cs 894.6 nm, Rb 795 nm) where magnetic cleanliness is critical.
Ace Photonics builds all three with matching footprints, AR bands, and windows—so you can migrate without redesigning your board.
895nm 1mW VCSELs hit a sweet spot for eye-safety, silicon-detector response, and compact optics in short-range sensing.
TO-Can = rugged, hermetic, easy heatsinking; great for labs, pilot runs, and harsh environments.
SMD = low Z-height, SMT throughput, tight module integration; watch reflow profiles and window films.
Non-magnetic = nickel-free, ceramic/glass stacks for quantum sensors (e.g., Cs 894.6 nm, Rb 795 nm) where magnetic cleanliness is critical.
Ace Photonics builds all three with matching footprints, AR bands, and windows—so you can migrate without redesigning your board.
Where 895nm 1mW VCSELs Shine
Short-range sensing & presence
Silicon detectors retain strong responsivity at 895 nm with low dark current.
1 mW output pairs with compact optics to deliver clean returns from matte surfaces without saturating the receiver.
Short duty-cycle pulsing simplifies Class 1 budgets.
Wearables & health interfaces
Near-IR penetrates slightly deeper than visible bands; with bandpass filters, ambient suppression improves SNR.
A diffuser and careful window selection reduce speckle and improve skin coupling.
Smart home & mobile robotics
Doorbells, locks, and floor robots use 895 nm for stable returns on wood, paint, and fabric.
Window geometries let you tailor FOV—tight for range, wide for presence—while staying inside a small power budget.
TO-Can Packaging (TO-46): Hermetic Workhorse
Best for: fast lab bring-up, harsh environments, long life builds
Thermal behavior at 895nm 1mW
Even modest optical power can shift wavelength if junction temperature drifts. TO-Cans conduct heat through a metal slug into your mount or chassis, keeping junction temps—and thus wavelength—tighter. Pulsed operation lowers average dissipation and helps aging stability.
Window options
Flat: lowest cost and height
Dome: gentle collimation, improved coupling into simple optics
Wedge: mitigates back-reflection/etalon fringes
All can carry AR coatings centered near 795 nm, 895 nm, or dual-band if you ship both lines.
Assembly tips
Socket, solder, or clamp.
Avoid alcohol floods on hot parts and hard wipes on coated lids.
Store with desiccant; clean trays prevent smudges and fiber fallout.
SMD Packaging: Board-Level Speed & Scale
Best for: compact modules, wearables, camera clusters, high-volume SMT
Thermal path for 895nm 1mW
Use a copper coin or dense thermal-via array under the thermal pad.
Keep solder fillets modest to avoid tilt; place the driver close with short, wide traces.
Maintain low inductance in the return path to suppress ringing.
Pick-and-place, AOI, reflow
Follow MSL storage; dry-pack when required.
Minimize double reflow on optics with delicate films.
AOI should verify coplanarity, lid alignment, and window edge integrity.
EMC/ESD hygiene
Fast edges radiate—use a grounded frame or top-side shield.
Snub the driver; keep loop areas tight.
Add low-capacitance TVS near the pins with a very short return.
Non-Magnetic Packaging: Built for Quantum Sensing
Best for: atomic magnetometers, cesium 894.6 nm D1 cells, rubidium 795 nm systems, NV centers—any build where ferromagnetic parts can bias the field.
How Ace Photonics builds it
Nickel-free plating (e.g., Cu-Pd-Au or TiW/Au), ceramic carriers, and glass/sapphire lids with AR bands near 795 nm and ~895 nm.
Avoid Kovar and other magnetic alloys; pins favor copper-based conductors with gold finishes.
Adhesives and solders selected for low magnetic signature (AuSn, SnAgCu options).
We document magnetic susceptibility targets so your lab can verify with a gaussmeter.
Why it matters
Even small magnetic biases near vapor cells shift lock points and degrade stability. A clean package is your first line of defense—before magnetic shielding and control loops.
Windows, Coatings, and Beam Shaping
Substrate choices
BK7: cost-effective, robust for most builds.
Sapphire: scratch-resistant, high thermal conductivity—great for field gear.
Fused silica: low birefringence, excellent UV-VIS-NIR transmission when sharing an optical path.
Coatings & geometry
Single-band AR near 795 nm or 895 nm to reduce cavity feedback and boost link budgets.
Dual-band AR if you share housings across wavelengths.
Wedge lids reduce etalon fringes; diffusers broaden spots and tame speckle.
Custom dome FFA (e.g., 10° full angle) and wedge (e.g., 1.5°) available.
Design Integration: Drivers, Safety, and EMI
Match the driver to VCSEL capacitance; control rise/fall times to curb overshoot.
Keep the return path directly under the emitter; add small series resistors at driver pins.
Plan for IEC 60825-1 Class 1: pulsed operation with low duty cycles yields generous margins at 895nm 1mW.
Fence-via rings and small loop areas improve EMI immunity when RF neighbors share the board.
Durability & Screening
Optional burn-in, powered temperature cycling, and damp-heat exposure.
Photometry tracks output power and wavelength drift over time.
Mechanical checks cover shock, vibration, and drop for handhelds.
All shipments carry traceable lot codes and cert packs.
Quick Selector: TO-Can vs SMD vs Non-Magnetic (for 895nm 1mW)
Thermal Path Examples (895nm 1mW)
TO-Can on a copper slug or small heat spreader; keep thermal pads thin to lower Rθ. A simple clamp into the chassis can pull heat quickly.
SMD with via-in-pad to an internal copper coin; fill and cap vias to improve planarity for AOI and coplanarity during reflow.
How Ace Photonics Customizes Your Build
VCSELs from single emitters to arrays in TO-Can, SMD, or fully non-magnetic builds.
Windows: flat / dome / wedge / diffuser; materials: BK7, fused silica, sapphire.
AR bands near 795 nm and 895 nm (single or dual).
Magnetic vs non-magnetic variants in the same footprint so you can swap without a board change.
Documentation: optical/electrical specs, coating curves, handling notes.
Quote Checklist (send this to speed sizing & DFM)
Wavelength target & tolerance (e.g., 895 nm ± x nm)
Optical power & duty cycle (1 mW nominal; pulsing details)
Beam spread or NA; diffuser needs
Window type (flat/dome/wedge/diffuser) & material
Preferred package (TO-Can, SMD, or non-magnetic)
Pinout, driver supply, MSL target
Screening level (burn-in, temp cycle, damp heat)
Special constraints (low outgassing, vacuum bake, magnetic susceptibility)
From Prototype to Mass Build
Feasibility call → confirm specs and constraints.
Drawing pack → mechanical dims, window stack, coating bands.
EVT lots with golden samples and handling notes.
DVT → lock traveler, SPC limits, QA plan.
PVT & mass → certificate pack per lot with spectra and power data.
FAQs (895nm 1mW Focus)
Q1. Can you supply 795 nm and 895 nm in the same footprint?
Yes. We keep housing, pinout, and window geometry fixed while swapping die and AR bands—ideal for mixed product lines.
Q2. Do you offer magnetic and non-magnetic versions?
Yes. Non-magnetic uses nickel-free stacks, ceramic carriers, and glass/sapphire lids; magnetic variants retain the footprint at lower cost.
Q3. What window options are available?
Flat, dome, wedge, or diffuser in BK7, fused silica, or sapphire. AR bands centered near 795 nm, 895 nm, or both.
Q4. How do you keep the beam stable over temperature?
By controlling thermal paths (slug, vias), duty cycle, and window coatings chosen for your temperature range.
Q5. Can you help with IEC 60825-1 Class 1 paperwork?
We provide optical power, pulse timing, and beam geometry data and can suggest layout tweaks (recessed apertures, diffusers).