An apparatus for baking a semiconductor wafer having a resist pattern thereon includes a baking oven in which the semiconductor wafer is placed and heated, and a first hot plate which is provided in the baking oven to heat an entire bottom surface of the semiconductor wafer. When operating in the analog mode, the apparatus comprises a processor that receives digital I, Q pairs relating to audio or data signals and performs FM demodulation to generate information content relating to the audio or data signals. The thin film unit is installed with a first circuit. The voucher is authenticated in a secure fashion to ensure redemption occurs according to the issuer’s specification. The optical fiber includes a fiber grating having a reflection center wavelength greater than the cutoff wavelength of the laser diode and having a half-width of reflection spectrum ranging from twice the spacing of longitudinal modes of the laser diode to 10 nm.