Speech recording is effected in a GSM phone handset by storing in a memory speech frames during the presence of speech, one or more SID frames during the absence of speech, and data representative of the duration of the absence of speech. In one aspect of the invention the free layer structure consists of only the cobalt iron layer and the cobalt niobium or cobalt niobium hafnium layer. The second MOS transistor having a gate terminal for receiving a bias voltage is coupled between the first node and a second power supply voltage. The lid may include an interior side. A slab waveguide is dimensioned and configured to fit within the recess, and the waveguide guides input light to and from the diffraction grating.