This paper reports a GaSb quantum-well-based widely tunable V-coupled-cavity laser (VCCL) targeting the 1.7-2.0 µm spectral range, which is significant for gas detection and biomedical applications. The VCCL employs a half-wave coupler for single-mode selection without a grating structure, enabling a wide range of wavelength tuning by current and temperature adjustments. The laser exhibits a record tuning range of 255 nm from 80 K (-193.15°C) to 330 K (56.8°C) with a high side-mode suppression ratio (SMSR) and delivers several milliwatts of output power. It is also compatible with packaging into transmitter optical sub-assemblies (TOSA) for augmented performance. This technology advancement in a tunable mid-infrared laser has significant potential for various spectroscopic applications.