  Using photometry collected with the Zwicky Transient Facility (ZTF), we are
conducting an ongoing survey for binary systems with short orbital periods
($P_{\rm b}<1\rm \,hr)$ with the goal of identifying new gravitational-wave
sources detectable by the upcoming Laser Interferometer Space Antenna (LISA).
Here, we present a sample of fifteen binary systems discovered thus far, with
orbital periods ranging from $6.91\rm\,min$ to $56.35\rm\,min$. Of the fifteen
systems, seven are eclipsing systems which do not show signs of significant
mass transfer. Additionally, we have discovered two AM Canum Venaticorum (AM
CVn) systems and six systems exhibiting primarily ellipsoidal variations in
their light curves. We present follow-up spectroscopy and high-speed photometry
confirming the nature of these systems, estimates of their LISA signal-to-noise
ratios (SNR), and a discussion of their physical characteristics.
