New arrival of birefringent filters

UltraOpto New Product Launch | Birefringent Filter, a Core Optical Component for High-End Spectral Tuning and Narrowband Filtering

UltraOpto has newly launched the Birefringent Filter, designed based on the core principle of polarization interference in birefringent crystals. It is a high-end core optical component in fields such as lasers, astronomical observation, and high-resolution spectral analysis. It can achieve precise output of narrowband monochromatic light and continuous tuning of laser wavelengths, and has the core characteristics of extremely narrow transmission bandwidth, wide tuning range, and high laser damage threshold, providing a highly reliable solution for high-precision wavelength control and spectral filtering.

The half-width of the product's transmission band can be as low as 0.1~1 angstrom, with full spectral filtering precision. Continuous tuning of the laser wavelength can be achieved by rotating around the normal line. The central wavelength tolerance is ±0.2nm, the clear aperture is >90%, the wavefront distortion is <λ/[email protected], with no stray light interference and excellent transmission efficiency. The Lyot-type structure with multi-crystal combination can achieve a larger transmission peak period, meeting the needs of wide-range tuning and adapting to precise wavelength control of oscillating light in laser cavities.

The core substrate is made of high-purity quartz crystal, which has a low thermal expansion coefficient, stable birefringent properties, high laser damage threshold, weak spontaneous fluorescence, and no background interference. For high-end scenarios, special birefringent crystals such as calcite and α-BBO can be customized to meet the needs of the full ultraviolet to infrared band. It is divided into two structures: single-stage crystal filter (simple structure, easy to integrate) and Lyot-type combined filter (narrowband, high precision, wide-range tuning). The crystal surface can be customized with anti-reflection coating to further improve light transmission efficiency, and the uncoated version can also be directly adapted to conventional optical paths.

Strict ultra-precision processing standards are implemented. The conventional circular sizes are Φ12.7mm and Φ25.4mm, and special shapes can be customized. The crystal thickness can be selected from 0.5mm to 8mm with a tolerance of ±0.005mm, and the diameter tolerance is +0/-0.2mm. The surface quality reaches the high standard of 20/10 MIL, the parallelism is <5 arcseconds, the crystal optical axis orientation is precise, and the edges are chamfered with 0.2~0.5mm×45° for protection to prevent chipping. The Lyot-type structure is spliced by optical contact method, with no gaps and no stray light. The angle between the polarizer and the crystal optical axis is precisely 45°, ensuring interference effect and batch consistency.

The products are fully tested by high-precision equipment such as polarization light detectors, spectrum analyzers, and laser wavelength tuning test benches before leaving the factory, covering core indicators such as transmission bandwidth, tuning range, and wavefront distortion. They have passed rigorous tests such as high and low temperature cycles, thermal shock, and mechanical vibration. The birefringent properties of the crystals do not drift under temperature changes and complex working conditions, and the structural stability is excellent, adapting to long-term continuous work in industrial and scientific research grades. It is widely used in laser system wavelength tuning, solar monochromatic light filtering in astronomical observation, high-resolution Raman/fluorescence spectral analysis, and can also be adapted to high-end scenarios such as laser processing, biomedical laser detection, and optical fiber communication. Spot supplies of mainstream crystal specifications are sufficient. The substrate, structure, and size can be customized non-standard, supporting small-batch sampling with stable delivery time, providing professional wavelength tuning and narrowband filtering solutions for high-precision optical systems.