The demand for infrared transmitting materials has grown steadily for several decades as markets realize new
applications for longer wavelength sensing and imaging. With this growth has come the demand for new and
challenging material requirements that cannot be satisfied with crystalline products alone. Chalcogenide materials,
with their unique physical, thermal, and optical properties, have found acceptance by designers and fabricators to
meet these demands.
No material is perfect in every regard, and chalcogenides are no exception. A cause for concern has been the
relatively low fracture toughness and the propensity of the bulk material to fracture. This condition is amplified
when traditional subtractive manufacturing processes are employed. This form of processing leaves behind micro
fractures and sub surface damage, which act as propagation points for both local and catastrophic failure of the
Precision lens molding is not a subtractive process, and as a result, micro fractures and sub surface damage are not
created. This results in a stronger component than one produced by traditional methods. New processing methods
have also been identified that result in an even stronger surface that is more resistant to breakage, without the need
for post processing techniques that may compromise surface integrity.
This paper will discuss results achieved in the process of lens molding development at Edmund Optics that result in
measurably stronger chalcogenide components. Various metrics will be examined and data will be presented that
quantifies component strength for different manufacturing processes.