We report the results of our studies on the optical and thermal properties of the mixture of sodium dodecyl sulfate (SDS) and orthophosphoric acid (H3PO4), which exhibits very interesting induced polymorphic smectic phases such as smectic-A, smectic-D, smectic-B, and smectic-E phases, sequentially when the specimen is cooled from its isotropic liquid phase. Different liquid crystalline phases observed in the mixture were studied using differential scanning calorimetry (DSC), X-ray, and optical microscopic techniques. The temperature variation of optical anisotropy has also been discussed. Helfrich potential and elastic moduli have been estimated in the smectic phase using Helfrich model.