NOVELTY - An optical assembly has polymeric surface(s) and a layer(s) of a cured encapsulant. The encapsulant, in the uncured liquid state, comprises high durability polymer(s) (HDP), unsaturated monomer(s) and/or oligomer(s), and photoinitiator(s).    USE - Optical assembly i.e. photovoltaic module comprising photovoltaic cell(s) or concentrating photovoltaic cell (claimed).    ADVANTAGE - A reliable, cost effective, encapsulated concentrating photovoltaic cell that has excellent dimensional stability and discoloration resistance, obviating the use of thermoplastic encapsulants and silicone encapsulants, is provided. The cured encapsulant is a non-tacky or tacky, resilient, soft, transparent, void-free, haze-free bonding layer. It has glass transition temperature of lower than 30, preferably lower than - 40 degrees C; light transmission through 500 mu m of cured mass of greater than or equal to 85% of original light intensity in the wavelength of 300-800 nm; tensile modulus of elasticity of 100-0.0001, preferably 100-0.01 MPa, as measured at 1 Hz at 23 or - 40 degrees C; shore hardness lower than 85, preferably lower than 20 A; and refractive index of 1.4-1.6. The photo/thermocurable liquid encapsulant formulation has a viscosity at 25 degrees C of 50-1000, 150-5000, or 250-10000 cP at a shear rate of 10/seconds. It is liquid at room temperature; cures readily when exposed to light and/or heat; has high degree of transparency, high resistance to yellowing and cracking when exposed to sunlight, enough softness (low shore hardness and low modulus of elasticity), flexibility to withstand the thermal mismatch between the transparent (amorphous) plastic materials and glass/photovoltaic silicon during thermal cycling, low haze, and excellent adhesion to transparent (amorphous) plastic materials, such as PMMA, cyclic olefin, and polycarbonate to glass and/or to silicon photovoltaic cell. The encapsulant formulation enables high speed and economical manufacturing of photovoltaic modules, without the need for lamination under high pressure and heat (as in the case with prior art, which employs ethylene vinyl acetate and polyvinyl butyral), and long curing periods and expensive surface treatments (as in the case with the addition of curing silicone elastomers). It has excellent adhesion to thermoplastic and thermosetting materials, without needing surface pretreatment, primer, or any other adhesion promoting steps. The cured layer of the encapsulant has adhesion peel strength to PMMA of greater than 1, greater than 3 pounds/linear inch; adhesion tensile strength to PMMA of greater than 0.001 kg/cm2. Unlike thermoplastic adhesives, the encapsulant requires minimal pressure or no pressure at all and usually flows and wets well at ambient, without needing external heat. The encapsulant has minimal thermal history during processing, since neither extrusion, nor high temperature lamination is required. This lowered thermal history provides polymer mass that has lower unsaturated groups, lower gel content, and lower weakened points.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) photo/thermocurable liquid encapsulant formulation for optical assemblies; and    (2) cured encapsulant mass prepared by providing photo/thermocurable liquid encapsulant formulation and curing the formulation.