Project Background & Technical Objectives
A leading scientific instrumentation manufacturer required custom, high-precision infrared (IR) objective lenses for integration into a next-generation analytical instrument platform. The application demanded extreme optical throughput across a specialized spectral range spanning the mid-wave (MWIR) and long-wave (LWIR) infrared bands.
Engineering and Performance Specifications
Optical Parameter | Engineering Target |
Effective Focal Length (EFL) | 8 μm |
F-Number | 0.8 |
Wavelength Coverage | 3 – 5 μm & 8 – 12 μm |
MTF Performance | MTF > 0.60 at 20 lp/mm |
Technical Challenges & Solutions
1. Eliminating Thin-Film Membrane Detachment
During initial validation, infrared broad-band anti-reflective (BBAR) coatings exhibited micro-peeling. Shanghai Optics isolated the root cause as a combination of high intrinsic mechanical stress in the film layers and substrate surface energy.
The Solution: We optimized coating chamber parameters, fine-tuning deposition temperatures and electron-beam acceleration voltages. This yielded a highly durable, low-stress multilayer structure that passed all rigorous adhesion and environmental durability tests.
2. Resolving Batch-to-Batch Color Variation
Minor layer thickness fluctuations led to visual color shifts in the visible spectrum (400 nm – 700 nm), despite perfect IR performance.
The Solution: Shanghai Optics redesigned the thin-film interference stack by introducing tightly toleranced non-active matching layers. This stabilized the residual reflection spectrum in the visible region, ensuring cosmetic consistency across all production batches.
Aligned Application-Specific Testing and Validation
To ensure high-precision performance, Shanghai Optics aligned its cleanroom testing protocols to match the exact operational conditions of the customer’s instrument.
- Spectral Range Alignment: QA protocols utilized specialized infrared spectrophotometers configured to evaluate performance specifically between 5.5 μm and 10.3 μm.
- Performance Verification: By measuring MTF values within this exact operational band, we guaranteed that factory data perfectly correlated with real-world instrument performance.
Optimize Your Infrared Optical Assembly
As a leading manufacturer of MWIR and LWIR objective lenses, Shanghai Optics provides the technical expertise required to balance spectral transmission with thin-film durability.
Contact our engineering team today to submit your custom specifications or request a design-for-manufacturability (DFM) review for your next infrared objective lens project.
