Quantum weak measurement technology has significantly advanced the detection limits of quantum precision measurement due to its minimal disturbance to the measured system and the weak value amplification effect. This technique has been successfully applied to phase difference and time difference measurements, resulting in a series of important achievements. Previous standard weak measurement typically uses only a single momentum parameter as the measurement pointer and relies on a single weak interaction to detect minute phase shifts. Although some studies have attempted to introduce quantum resources to further enhance the amplification factor and measurement precision, their practical applications are hindered by the challenges associated with quantum state preparation. Therefore, practical quantum weak measurement systems still require in-depth research and exploration to overcome these technical bottlenecks.

In this study, we propose and experimentally validate a dual -parameter quantum weak measurement scheme based on tunable spectral control and iterative weak interactions. Theoretical analysis demonstrates that adjusting the spectral width and the number of weak interactions can effectively enhance the weak value amplification effect. Experimentally, a phase weak measurement system based on iterative weak interactions is constructed using a tunable light source as an optical input. The setup includes three sets of half-wave plates (HWPs) to realize triple weak interactions. By fixing the post selection angle and rotating the HWPs to introduce a weak phase delay, high-precision detection of the phase shift is achieved by monitoring the variations of both the spectral shift and light intensity. Experimental results indicate that at a spectral width of 700 GHz, the momentum parameter M achieves an optimal phase difference measurement accuracy of 4.06×10^–8 rad, which is 2.78 times higher than that of single weak interaction (SWI). As the spectral width decreases, the signal-to-noise ratio (SNR) gradually degrades, causing the shift signal of parameter M to be submerged in the spectrometer’s electronic noise. This necessitates a switch to the intensity parameter I for detection. When a narrow-linewidth source with a linewidth of 500 kHz is used, the intensity parameter I enables phase difference measurements at a level of 5.99×10^–7 rad while maintaining an SNR of 17.4 dB. Its measurement precision is 2.97 times higher than that of SWI. In optical experiments, the optical phase can serve as a proxy for other physical quantities such as displacement, temperature, and magnetic field strength. Therefore, this scheme provides crucial technical support for enhancing quantum precision sensing in practice.