YT-2120 Optical Fiber-Grade Synthetic Quartz Tube — Low-OH Fused Silica with Customisable Refractive Index
LUMIGLAS® YT-2120 is an optical fiber-grade synthetic quartz tube produced from 6N fused silica (SiO₂ ≥99.9999%) with OH hydroxyl content <1 ppm and all metallic impurities controlled below 0.005 ppm (wt). Refractive index (Δn) is customisable for specialty fiber preform design. Available in three sub-grades — liner tube, small sleeve and large sleeve — covering OD φ10–90 mm with lengths up to 3000 mm. Used in OVD, VAD, MCVD and PCVD fiber preform processes and specialty optical fiber manufacturing.
Description
The LUMIGLAS® YT-2120 optical fiber quartz tube is an optical-grade synthetic fused silica tube engineered for optical fiber preform fabrication and specialty optical fiber manufacturing. Produced from 6N-grade synthetic fused silica (SiO₂ ≥99.9999%), the YT-2120 controls OH hydroxyl content to below 1 ppm — eliminating the water peak absorption at 1383 nm that limits optical transmission in the E-band and directly affects single-mode fiber attenuation. Furthermore, all ten major metallic impurities are held below 0.005 ppm (wt), meeting the contamination requirements of telecommunications-grade and specialty fiber preform processes.
Unlike semiconductor-grade quartz tubes that prioritise diffusion contamination control, the YT-2120 is specifically formulated for optical fiber applications — combining ultra-low OH with a customisable relative refractive index (Δn) that allows process engineers to tailor the preform substrate to their target fiber refractive index profile. The YT-2120 covers three sub-grades in a single model: liner tube (OD 10–40 mm), small sleeve tube (OD 40–60 mm) and large sleeve tube (OD 60–90 mm), all produced to tight geometric tolerances suitable for OVD, VAD, PCVD and MCVD fiber preform deposition processes.
Technical Specifications — YT-2120 Optical Fiber Quartz Tube
| Parameter | Value / Grade |
|---|---|
| Product Type | Optical fiber-grade synthetic quartz tube / low-OH fused silica tube |
| Material | Synthetic fused silica — SiO₂ ≥99.9999% (6N grade) |
| OH Hydroxyl Content | <1 ppm — eliminates the 1383 nm water peak absorption band |
| Metallic Impurities | All major elements (Li, Na, K, Mg, Ca, Cu, Al, Cr, Fe, Ti) <0.005 ppm (wt) |
| Relative Refractive Index (Δn) | Customisable — specify target Δn for specialty fiber preform design |
| Max. Service Temperature | ~1200°C continuous service |
| Thermal Expansion | 0.55 × 10⁻⁶ /°C — near-zero thermal expansion |
| OD Range | φ10–90 mm (three sub-grades) |
| Wall Thickness | 1.0–30 mm |
| Max. Length | Up to 3000 mm (sub-grade dependent) |
| Material Certificate | Full impurity analysis Certificate of Conformity (CoC), supplied as standard |
Major Metallic Impurity Content & Hydroxyl — YT-2120
All values in ppm (wt). OH hydroxyl content is a critical parameter for optical fiber applications — the YT-2120 controls OH to <1 ppm to eliminate the 1383 nm water peak. Full impurity analysis CoC provided as standard.
| Grade | Li | Na | K | Mg | Ca | Cu | Al | Cr | Fe | Ti | OH (ppm) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| YT-2120 | <0.001 | <0.005 | <0.002 | <0.001 | <0.003 | <0.001 | <0.003 | <0.001 | <0.002 | <0.001 | <1 |
Optical Material Parameters
| Parameter | YT-2120 Value |
|---|---|
| Relative Refractive Index (Δn) | Customisable — specify target Δn when ordering |
| OH Hydroxyl Content (ppm) | <1 ppm |
OH <1 ppm eliminates the water peak absorption at 1383 nm, which is critical for E-band transmission and low-loss single-mode fiber. Customisable Δn enables refractive index profile design for polarisation-maintaining, photonic crystal and other specialty fiber types.
Geometric Specifications & Dimensional Tolerances — Three Sub-Grades
OD = outer diameter · WT = wall thickness. Three sub-grades in one model — specify sub-grade and OD × WT × Length (mm) when ordering. Custom dimensions available.
| Parameter | Sub-Grade | ||
|---|---|---|---|
| Liner Tube OD 10–40 mm |
Small Sleeve OD 40–60 mm |
Large Sleeve OD 60–90 mm |
|
| OD (mm) | 10–40 | 40–60 | 60–90 |
| WT (mm) | 1.0–10 | 2–15 | 2–30 |
| OD Tolerance (mm) | ±0.50 | ±0.80 | ±2.00 |
| WT Tolerance (mm) | ±0.30 | ±0.30 | ±3.00 |
| Out-of-Roundness (mm) | ≤0.15 | ≤0.40 | ≤0.40 |
| Wall Eccentricity (mm) | ≤0.15 | ≤0.45 | ≤0.45 |
| CSA Relative Difference | ≤6.0% | ≤6.0% | ≤6.0% |
| Bow (mm/m) | ≤0.70 | ≤0.70 | ≤0.70 |
| Length (mm) | ≤3000 | ≤3000 | ≤2000 |
* Custom OD, WT, length and refractive index available on request. Specify sub-grade + OD × WT × Length (mm) + target Δn when enquiring.
Why Low-OH Synthetic Quartz Tube Matters for Optical Fiber
OH hydroxyl groups in fused silica create a characteristic absorption peak at 1383 nm — precisely within the E-band used in wavelength-division multiplexing (WDM) telecommunications systems. Even small concentrations of OH at the ppm level in the preform substrate tube can increase fiber attenuation at this wavelength, narrowing the usable transmission bandwidth of the deployed fiber. Because the YT-2120 controls OH to below 1 ppm, it eliminates this water peak at source — allowing fiber manufacturers to produce low-water-peak (LWP) and zero-water-peak (ZWP) fiber to ITU-T G.652D and G.657 specifications.
OH <1 ppm — Zero Water Peak
OH content below 1 ppm eliminates the 1383 nm water peak absorption — enabling E-band transmission and supporting ITU-T G.652D / G.657 low-water-peak fiber specifications.
Customisable Refractive Index (Δn)
The relative refractive index Δn can be specified to order — critical for polarisation-maintaining fiber, photonic crystal fiber, sensing fiber and other specialty fiber types requiring a precise substrate-core index contrast.
6N Purity — ppb Metallic Impurity Control
All metallic impurities are held below 0.005 ppm (wt) — preventing transition metal absorption and scattering loss contributions that degrade fiber attenuation in the O, E, S, C and L transmission bands.
Three Sub-Grades — One Model
Liner tube (OD 10–40 mm), small sleeve (OD 40–60 mm) and large sleeve (OD 60–90 mm) sub-grades are available within the YT-2120 model — covering inner and outer preform substrate roles in a single qualified material grade.
Typical Applications
- ▸Optical fiber preform substrate tubes — OVD, VAD, PCVD and MCVD deposition processes for telecommunications single-mode and multi-mode fiber preforms
- ▸Low-water-peak and zero-water-peak fiber — ITU-T G.652D and G.657 compliant fiber preform substrate where OH <1 ppm at the substrate eliminates the 1383 nm water peak
- ▸Polarisation-maintaining (PM) fiber preforms — high-precision liner and sleeve tubes with specified Δn for PANDA, bow-tie and elliptical-core PM fiber preform designs
- ▸Specialty and sensing fiber preforms — photonic crystal fiber, erbium-doped fiber, distributed sensing fiber and other specialty fiber types requiring custom refractive index profile design
- ▸Fiber preform drawing tower quartz components — sleeve tubes and liner tubes used as structural and containment components in fiber drawing tower assemblies
Technical Document & Download
📄 Technical Datasheet — YT-2120
Full impurity data, OH content, optical parameters, geometric tolerance table and sub-grade reference.
Frequently Asked Questions
Request a Quote — LUMIGLAS® YT-2120 Optical Fiber Quartz Tube
Specify: Sub-grade + OD × WT × Length (mm) + Target Δn · Custom RI and dimensions welcome
