The next generation of detectors at lepton colliders will emphasize precision
for all sub-detector systems. One of the physics challenges for new detectors is to
distinguish W and Z vector bosons in their hadronic decay mode. This requires
a di-jet mass resolution of the order of the natural width of these bosons
and hence a jet energy resolution of about 3%. For hadron calorimetry this
means an energy resolution a factor of two better than previously achieved to
date by any large-scale experiment.

A novel approach to achieving superior hadronic energy resolution is based on
a homogeneous hadronic calorimetry (HHCAL) detector concept with dual read out.
Dual read out means that Cerenkov and scintillation light is read out
separately and using the correlation of these two measurements is used to
obtain superior hadronic energy resolution. This HHCAL detector concept
has a total absorption nature, so its energy resolution is not limited by the
sampling fluctuations. Fine segmentation allows the application of particle
flow algorithms (PFA) to further improve the resolution.
Active materials, such as scintillating crystals, glasses or ceramics, may
be used to construct an HHCAL and a detector research and development program
over the next years to develop cost-effective crystal scintillators of adequate
size, density, scintillation and optical properties to realize a HHCAL
detector concept for future high energy physics (HEP) experiments has been
proposed.

In this seminar we describe the concept of a homogeneous calorimeter with
dual read out, we describe the properties of the materials and photo-detectors
that are required and present results obtained with a full geant 4
simulation and exposing single crystals to test beams.