Semiconductor Optical Amplifiers (SOAs) are electrically pumped semiconductor devices that provide optical gain in a travelling‑wave configuration. They operate similarly to laser diodes but use antireflection (AR) coatings and angled or curved waveguides to suppress cavity feedback. Light is amplified in the singlemode waveguide with strong overlap between the guided mode and the carrier‑injected active region.
Typical telecom SOAs operate at O-band (around 1310nm) and C-Band (around 1550nm) and can provide up to ~30 dB gain, limited by ASE and strong gain saturation. Saturation and carrier‑induced refractive index changes also enable nonlinear functions such as wavelength conversion.
Our range is broader since we offer SOAs from QD Laser at 1060nm while SemiNex have devices at 1280nm, 1310nm, 1520nm, 1550nm and 1595nm.
Comparing SOAs with EDFAs
Using an SOA offers a number of key advantages compared to Erbium Doped Fibre Amplifier (EDFA), although there are also limitations:-
- Form factor: SOAs offer chip scale architecture; low cost and easy integration.
- Output power: Output power of SOAs is lower than can be achieved with EDFAs.
- Drive conditions: Low electrical power for SOAs with operating currents up to hundreds of mA;
- Dynamics: Nanosecond‑scale carrier lifetime → fast gain and phase response.
- Nonlinearities: SOAs exhibit strong SPM and FWM at moderate powers.
- Noise: Higher noise figure than EDFAs.
- Polarisation: SOAs have Polarisation Dependant Gain (PDG), although this can be compensated by system design.
- Modulation: Direct current modulation supports multi Gbit/s data rates.
Reflective SOAs and Gain Chips
Reflective SOAs (RSOAs) use one high reflectivity facet and one AR facet, enabling double‑pass gain. They are widely deployed in WDM‑PON as colourless ONUs, where a downstream CW carrier is remodulated upstream via gain modulation.
Semiconductor gain chips, similar in structure, are optimised for external cavity lasers (ECLs) rather than single‑pass amplification.
Ultra-High Power SOAs
SemiNex’ Ultra-High Power O-band SOA technology is built on their advanced and proprietary epi and optical waveguide structures which allow maximum output powers in excess of 30dBm (1 Watt) saturation output power whilst maintaining greater than 25% Power Conversion Efficiency (PCE) at 50°C.
This exciting technology is the foundation for high speed and high data throughput co-packaged optics (CPO); Silicon Photonic Integrated Circuits (Si PICs); and External Laser Small Form Factor Pluggable (ELSFP) high density photonic engines in next-generation AI data centre infrastructure and high-performance computing.
The power levels available are also ideal for Frequency Modulation Continuous Wave (FMCW) LiDAR applications, increasing range to >250m in all weather and lighting conditions.
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Product Brief: SemiNex 1280 to 1595nm 14-pin BF package SOAs |
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Product Brief: SemiNex 1280 to 1595nm chip and chip-on-carrier SOAs & RSOAs |
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Product Brief: SemiNex 1310nm ultra-high power chip-on-carrier SOAs |
For more information on SemiNex and QD Laser SOA and RSOA solutions please Contact Us to discuss your application and learn about the latest developments.
