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Materials Science in Additive Manufacturing Additive manufacturing of active optics

A B C

D E

Figure 4. Various applications based on span angle control with active beam steering. (A) Photonic‑electronic integrated circuit‑based coherent LiDAR
engine. Adapted with permission from Lukashchuk et al. (Copyright © 2024, Lukashchuk et al.). (B) PCSEL for LiDAR applications. Adapted with
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permission from Wang et al. (Copyright © 2024, American Chemical Society). (C) Beam steering with a non-linear optical phased array antenna.
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Adapted with permission from Busschaert et al. (Copyright © 2019, American Chemical Society). (D) Metagrating-integrated laser for microscopy.
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Adapted with permission from Juodėnas et al. (Copyright © 2023, Juodėnas et al.). (E) High‑resolution multispectral SLM based on tunable Fabry‑Perot
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nanocavities. Adapted with permission from Mansha et al. (Copyright © 2022, Mansha et al.)
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Abbreviations: ASIC: Application‑specific integrated circuit; CIRC: Circulator; COL: Collimator; DBR: Distributed Bragg reflector; DSO: Digital storage
oscilloscope; EDWA: Erbium‑doped waveguide amplifier; LiDAR: Light detection and ranging; PCSEL: Photonic‑crystal surface‑emitting laser; RSOA:
Reflective semiconductor optical amplifier; SLM: Spatial light modulator; TIR: Total internal reflection
In LiDAR systems, a wider span angle increases coverage high-angle deflection mechanism (Figure 4E), enabling
area, making it ideal for broad environmental scans. high-contrast microscopy with improved resolution. 35
Conversely, a narrower span angle enhances resolution,
enabling the capture of more detailed images of specific 3. Active materials for realizing light-
regions of interest (Figure 4A). This adaptability is also emitting 3D optics
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critical in microscopy, where dynamic adjustments in span The interaction between optical waves and various
angle allow researchers to switch between wide-area scans materials enables unique optical phenomena, and additive
and high-resolution imaging as needed (Figure 4B). manufacturing technologies have enhanced the ability to
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For the applications of display, SLM is the most relevant realize light-emitting properties through precise control
technology for dynamic wavefront manipulation, which over refraction, reflection, absorption, and transmission.
is intrinsically monochromatic. Based on liquid crystal- Materials such as polymers, metals, nanocomposites,
tunable Fabry–Perot nanocavities, the high‑resolution ceramics, and semiconductors play crucial roles in tuning
multispectral SLM can be developed to realize multi- light-emitting properties in 3D-printed optical systems. 36,37
spectral programmable beam steering (Figure 4C). The following sections discuss the major classes of active
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Recent advancements in active beam steering have shown materials and how they are integrated into 3D optics for
that systems integrated with photonic-crystal surface- applications ranging from micro-lasers to photonic crystals.
emitting lasers can significantly improve flexibility and
efficiency by dynamically controlling span angles without 3.1. Polymers for light-emitting 3D optics
relying on bulky mechanical components (Figure 4D). Polymers are among the most versatile materials used in 3D
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Furthermore, metagrating-integrated lasers provide a optical systems due to their optical transparency, flexible

Volume 3 Issue 4 (2024) 6 doi: 10.36922/msam.5748