Table 1 Comparison of different spatial mode multiplexer types

All fiber PL

<0.7 dB

<0.7 dB

1.2 dB

125 mm long

^42,43

Glass inscribed PL

<1.5 dB

<2.5 dB

–

50 × 15 × 10 mm

³⁵

MPLC

>4 dB

–

1.2 dB

100 mm³ to 10 cm³

^44,45,46

3D printed microscale PL

<3.3 dB, typical 2.67 dB

<5.4 dB, typical 4.8 dB

4.43 dB

Ø100 µm × H375 µm

This work