Measuring the spectral properties of an optical frequency comb is among the most fundamental tasks of precision metrology. In contrast to general single-parameter measurement schemes, we demonstrate here single shot multi-parameter estimation of an optical frequency comb at and beyond the standard quantum limit. The mean energy and the central frequency as well as the spectral bandwidth of ultrafast pulses are simultaneously determined with a multi-pixel spectrally resolved (MPSR) apparatus, without changing the photonics architecture. Moreover, using a quantum frequency comb that intrinsically consists of multiple squeezed states in a family of Hermite–Gaussian spectral/temporal modes, the signal-to-noise ratios of the multiple spectral parameters estimation can surpass the standard quantum limit. Combining our multi-pixel detection scheme and the multimode entangled resource could find applications in ultrafast quantum metrology and multimode quantum information processing.

测量光学频率梳的光谱特性是精密计量的最基本任务之一。与一般的单参数测量方案相反，我们在此处展示了在标准量子极限及以上的光学频率梳的单发多参数估计。使用多像素光谱分辨（MPSR）装置可同时确定超快脉冲的平均能量和中心频率以及光谱带宽，而无需更改光子学体系结构。此外，使用本质上由Hermite–Gaussian光谱/时间模式族中的多个压缩态组成的量子频率梳，多个光谱参数估计的信噪比可以超过标准量子极限。