• A GaSb-based two-section integrated optical chip operating at ~2 μm was designed and fabricated, demonstrating stable mode-locked operation.
• The chip exhibits both near optical soliton states and multi-peak optical soliton states, confirmed by numerical fitting with pure fourth-order soliton approximation.
• This work provides a pathway for developing high-performance near-mid infrared mode-locked integrated optical chips with soliton capabilities.
• The findings have potential applications in optical communications, infrared countermeasures, and gas environment monitoring.