How to choose a anamorphic lens?
Choosing a suitable anamorphic lens requires comprehensive consideration of application scenarios, optical parameters, and performance indicators. Here are the key selection points:
Category selection
anamorphic lenses are mainly divided into two types: reflective and transmissive:
Reflective (mainstream):
Piezoelectric deformable mirror (PDM): Suitable for high-power laser systems, it achieves deformation through piezoelectric ceramic drive. MEMS (Micro Electro Mechanical) deformable mirror: Fast response speed, suitable for precision calibration.
Double piezoelectric deformable mirror: suitable for small and medium-sized aperture systems.
key parameters
Number and arrangement of driver units:
The more units there are, the stronger the correction ability (for example, 19 units are suitable for low order aberrations, and 140 units or more can correct high-order aberrations).
The hexagonal array covers more evenly, reducing blind spots in calibration.
Effective mirror size:
It is necessary to match the optical path aperture of the system, usually the mirror diameter is 20% -30% larger than the beam diameter.
Single actuator performance:
The maximum deformation determines the range of aberration correction, and the response time needs to match the bandwidth requirements of the control system (such as MEMS in microseconds and piezoelectric in milliseconds).
Linearity and hysteresis:
Linearity affects the accuracy of open-loop control, and hysteresis needs to be reduced through closed-loop control or feedforward compensation.
Coating and power tolerance:
The reflectivity of the MEMS deformable mirror metal film coating is greater than 95%, but the continuous laser power needs to be limited to the hundred watt level; Piezoelectric deformable mirrors can withstand higher power but require water cooling.
Special applications
Astronomical observation: The adaptive secondary mirror integrated in the position of the telescope secondary mirror can achieve dynamic correction.
Laser system: material temperature resistance, aging resistance (such as PC or PMMA material) and optical design (such as dual lens design) shall be considered.
