Cost-effective fabrication of As40Se60 glass lenses enabled by SPS-SPDT process

Abstract

In this paper, we prepare chalcogenide glass (ChG) discs with As40Se60 composition employing spark plasma sintering (SPS) with the advantage of higher raw materials utilization ratio compared with conventional coring and cutting processes. The hardness, composition, structure of the ChG discs are evaluated by HVS, EDS, XRD, Raman characterizations. The Vickers hardness of SPS glass (140.6 HV) is slightly lower than that of base glass. EDS data show that the atomic ratio of SPS glass does not deviate from the base glass. XRD and Raman results confirm that the SPS glass still retains the original amorphous structure. By ultra precision single point diamond turning (SPDT) method, an aspheric lens is fabricated from the SPS glass discs with the lens profile perfectly matched with the design. The modulation transfer function (MTF) of the aspheric lens within the full field of view is above 31%, which is comparable to base glass lenses and indicates lens performance satisfies the requirement of practical imaging devices.