1.What Material Is Best for Subsea Optical Dome Port? | Felix Glass
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- Oct 16,2026
What material is best for subsea optical dome port?
Selecting the right substrate is critical for subsea dome port performance, pressure resistance and service life. The three common optical materials are C-axis Sapphire, JGS1 Fused Silica and BK7 optical glass. Acrylic is not recommended for deep-water pressure applications.
C-axis Sapphire
Sapphire is the top choice for 7000m abyssal deployment. It features outstanding compressive strength, excellent scratch resistance and stable optical transmission under high hydrostatic pressure. It resists seawater corrosion well. The main downside is higher raw material and machining cost.
JGS1 Fused Silica
JGS1 fused silica is ideal for 3000m mid-depth ROV and AUV projects. It delivers balanced optical performance, good seawater resistance and competitive pricing. For 7000m service, fused silica dome needs reinforced wall geometry and full FEA validation before production.
BK7 Optical Glass
BK7 has lower compressive strength. It is only acceptable for short-duration, shallow-water missions with strict annealing treatment. Not suitable for 7000m ultra-deep use.
Acrylic PMMA
Acrylic suffers creep deformation under high pressure. It is forbidden for 3000m and 7000m subsea dome applications.
Quick Material Selection Guide
- 7000m long-term deep sea → C-axis Sapphire
- 3000m commercial inspection ROV → JGS1 Fused Silica
- Short mission, limited budget, shallow depth only → BK7 (with limitation)
FAQ
Q: Is sapphire better than fused silica for underwater dome?
A: Sapphire has superior compressive strength for ultra-deep 7000m. Fused silica offers cost advantage for mid-depth 3000m projects.
Q: Can BK7 glass be used for 7000m dome port?
A: No, BK7 does not have enough compressive strength for 700 bar pressure.
Q: Does seawater corrode fused silica or sapphire?
A: Both materials have excellent resistance to seawater corrosion.
Q: Can we add AR coating on sapphire and fused silica domes?
A: Yes, broadband AR anti-reflection coating can be applied on both substrates.
Q: Are your dome ports custom size?
A: Yes, custom diameter from 20mm to 60mm available.
CTA: Tell us your working depth and target wavelength, our engineers recommend suitable material for your optical dome port.
Related Subsea Dome Products
3000m Deep Sea Optical Dome Port
7000m Ultra Deep Sea Optical Dome Port
Flanged Optical Dome Port | Integrated One-Piece Flange Subsea Dome
Need Custom Subsea Optical Dome Port?
Tell us your working depth and target wavelength, our engineers recommend suitable material for your optical dome port.
Get Material RecommendationRelated reading: What is FEA simulation for subsea dome port?
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