A step-and-repeat nanoimprint lithography (SR-NIL) process on a pre-spin-coated film is employed for the fabrication of an integrated optical device for on-chip spectroscopy. The complex device geometry has a footprint of about and comprises several integrated optical components with different pattern size and density. Here, a new resist formulation for SR-NIL was tested for the first time and proved effective at dramatically reducing the occurrence of systematic defects due to film dewetting, trapped bubbles, and resist peel-off. A batch of 180 dies were imprinted, and statistics on the imprint success rate is discussed. Devices were optically characterized and benchmarked to an identical chip that was fabricated by electron-beam lithography. The overall performance of the imprinted nanospectrometers is well-aligned with that of the reference chip, which demonstrates the great potential of our SR-NIL for the low-cost manufacturing of integrated optical devices.