  We study the phase retrieval problem within the broader context of analytic
functions. Given a parameter $\theta \in \mathbb{R}$, we derive the following
characterization of uniqueness in terms of rigidity of a set $\Lambda \subseteq
\mathbb{R}$: if $\mathcal{F}$ is a vector space of entire functions containing
all exponentials $e^{\xi z}, \, \xi \in \mathbb{C} \setminus \{ 0 \}$, then
every $F \in \mathcal{F}$ is uniquely determined up to a unimodular phase
factor by $\{ |F(z)| : z \in e^{i\theta}(\mathbb{R} + i \Lambda) \}$ if and
only if $\Lambda$ is not contained in an arithmetic progression
$a\mathbb{Z}+b$. Leveraging this insight, we establish a series of consequences
for Gabor phase retrieval and Pauli-type uniqueness problems. For instance,
$\mathbb{Z} \times \tilde{\mathbb{Z}}$ is a uniqueness set for the Gabor phase
retrieval problem in $L^2(\mathbb{R}_+)$, provided that $\tilde{\mathbb{Z}}$ is
a suitable perturbation of the integers.
