# Double swept band selective excitation

## TL;DR

This paper introduces a novel double sweep method for designing band selective excitation and rotation pulses in high-resolution NMR, enabling precise control over specific frequency bands with improved refocusing techniques.

## Contribution

It presents a new pulse sequence design that achieves band selective excitation and x rotations using double sweep and adiabatic inversions, advancing NMR pulse engineering.

## Key findings

- Successful experimental excitation profiles for residual HDO signal
- Effective refocusing of linear phase dispersion
- Enhanced selectivity over desired frequency bands

## Abstract

The paper describes the design of band selective excitation and rotation pulses in high resolution NMR by method of double sweep. We first show the design of a pulse sequence that produces band selective excitation to the equator of Bloch sphere with phase linearly dispersed as frequency. We show how this linear dispersion can then be refocused by nesting free evolution between two adiabatic inversions (sweeps). We then show how this construction can be generalized to give a band selective $x$ rotation over desired frequency band. Experimental excitation profiles for the residual HDO signal in a sample of $99.5\%$ D$_2$O are obtained as a function of resonance offset.