Diffractive optical elements (DOEs) are the mediators that shape and divide the laser beams in an energy-efficient way. They also allow the user to accurately control the phase across the aperture and design the most complicated intensity profiles.
However, to meet the requirement of the client, many top-notch optic suppliers provide customized DOEs in different shapes, sizes, features, and functionalities. And, here’s the detailed note on the same:
- Analyze The Problem And The Requirement Of The Client: In this step, the optical manufacturer first analyzes the problem and understands the viability of the client’s specifications. They’ll also check whether the requirements of the client are matching with their existing range of off-the-shelf diffractive optical elements. Once the problem is analyzed and the specifications are deemed viable, the next step is to proof-of-concept experiments.
- Design The Outline Of DOE and Perform Simulations: Professional optic suppliers typically use computational design methods like Iterative Fourier Transform Algorithms (IFTA), direct binary search (DBS) algorithms, and gradient search algorithms to design the DOEs. These methods are ideal ways to approach those problems that require high-levels of complexity at a low budget.
- Fabrication Process Of DOEs: Depending on the client’s specifications, the volume of production, budget, and degree of precision, the fabrication technology is chosen. The steps of the conventional and most common lithography technology are as follows:
- First, the design data is optimized in order to minimize the fabrication error dependency.
- Once the data is optimized, E-beam direct writing lithography is used to reduce the size of the diffractive optics.
- Now, the manufacturer uses the etching technique (like iron plating or electroplating) in order to create target surface structures onto the substrate material. This technique also helps to generate tools for replication processes which is useful in injection molding and nano-imprinting.
- The results of Replication are verified with the initial specification made by the client. If all the features are found correct, then the DOEs are fabricated and assembled in the main product.
- The Quality Assurance Process: To meet the quality standards, the optic supplier will personally verify the quality and functionality of the DOE once it is fabricated. On the other hand, when the production volume is large, then the role of experienced scientists comes into the picture. The scientist will monitor the key properties of DOE using automated equipment.
The process of engineering advanced DOEs involves a number of complex techniques and equipment. So the thumb rule says – Better the fabrication, better is the durability!