  Gravitational lensing is the phenomenon where the presence of matter (called
a lens) bends the path of light-like trajectories travelling nearby. Similar to
the geometric optics limit of electromagnetic waves, gravitational lensing of
gravitational waves (GWs) can occur in geometric optics condition when GW
wavelength is much smaller than the Schwarzschild radius of the lens i.e.
$\lambda_{GW} \ll$ R$^{\rm s}_{\rm lens}$. This is known as the strong-lensing
regime for which a multiple-image system with different magnifications and
phase-shifts is formed. We developed $\texttt{GLANCE}$, Gravitational Lensing
Authenticator using Non-modelled Cross-correlation Exploration, a novel
technique to detect strongly lensed GW signals. We demonstrate that
cross-correlation between two noisy reconstruction of polarized GW signals
shows a non-zero value when the signals are lensed counterparts. The relative
strength between the signal cross-correlation and noise cross-correlation can
quantify the significance of the event(s) being lensed. Since lensing biases
the inference of source parameters, primarily the luminosity distance, a joint
parameter estimation of the source and lens-induced parameters is incorporated
using a Bayesian framework. We applied $\texttt{GLANCE}$ to synthetic strong
lensing data and showed that it can detect lensed GW signals and correctly
constrain the injected source and lens parameters, even when one of the signals
is below match-filtered threshold signal-to-noise ratio. This demonstrates
$\texttt{GLANCE}'$s capability as a robust detection technique for strongly
lensed GW signals and can distinguish between lensed and unlensed events.
