Compact dual-band spectral analysis via multiplexed rotated chirped volume Bragg gratings

TL;DR

This paper introduces an innovative multiplexed rotated chirped volume Bragg grating device, called X-CBG, enabling compact dual-band spectral analysis in visible and near-infrared ranges for advanced microscopy and sensing applications.

Contribution

The paper presents the design and implementation of multiplexed rotated CBGs (X-CBGs) that extend spectral analysis capabilities without increasing device volume or complexity.

Findings

Enables dual-band spectral analysis in a compact form factor.

Operates effectively in visible and near-infrared spectral windows.

Suitable for nonlinear microscopy and materials sensing.

Abstract

Chirped Bragg volume gratings (CBGs) offer a useful alternative for spectral analysis, but increasing the bandwidth necessitates increasing the device area. In contrast, recently developed rotated CBGs (r-CBGs), in which the Bragg structure is rotated by $45^{\circ}$ with respect to the device facets, require increasing only the device length to extend the bandwidth, in addition to the convenience of resolving the spectrum at normal incidence. Here, we multiplex r-CBGs in the same device to enable spectral analysis in two independent spectral windows without increasing the system volume. This new device, which we term an X-CBG, allows for compact multi-band spectroscopy in contiguous or separated spectral windows in the visible and near-infrared for applications in nonlinear microscopy and materials identification and sensing.