Table 1.

Characteristics of hydrogel-based optical fibres and waveguides reported in the literature.

Ref.	Material	Type	Dimensions	Optical loss
This	Agarose	Structured fibre	0.64 mm core, 2.5 mm cladding (diameter)	3.23 dB/cm(633 nm)
4	Agarose	Rib waveguide	130 × 130 µm² (cross-section area)	13 dB/cm(633 nm)
23	Gelatin core, agarose cladding	Planar waveguide	2 µm–2 mm core (thickness)	N/A
7	Polyethylene glycol diacrylate (PEGDA)	Planar waveguide	1 × 4 mm² (cross-section area)	0.17–0.68 dB/cm(450–550 nm)
18	PEGDA	Planar waveguide	1.1 ×5 mm² (cross-section area)	1.7–2.8 dB/cm(450–750 nm)
1	PEGDA core, alginate cladding	Fibre	0.2–1 mm core, 0.4–1.2 mm cladding (diameter)	0.3 dB/cm(492 nm)
6	PEGDA core, alginate cladding	Fibre	0.2–2 mm core, 0.3–2.2 mm cladding (diameter)	2.6–8.3 dB/cm(532 nm)
19	PEGDA core, alginate cladding	Fibre	0.2–2 mm core, 0.3–2.2 mm cladding	1–6 dB/cm(532 nm)
20	Alginate-polyacrylamide	Fibre	0.4–1.1 mm core, 0.9–2.2 mm cladding	0.45 dB/cm(532 nm)