NO
Set top box is basically used to convert the digital signals broadcasted by digital signal broadcasters to analog signals, in case you wish to have your analog tv, but would like to have an access to digital channels. Digital channels definitely have better quality signals than analog and therefore you will have a better picture quality and signal quality even though you have converted the digital signals to analog.
Digital converter boxes are used to convert digital signals to analog and were required to access tv signals for all analog televisions starting in 2011. Digital Convertor boxes are widely available at local retailers such as Target, Best Buy, HH Greg, Sears, Walmart, Radio Shack and more.
if you are looking for Photonic converter from electronics that means a device which can convert electronic signal to photonics. photonics stands for application of light whether it may be light generation transmission or processing of light signals.
The set top box that your provider gives you is what converts the Digital signal to the analog signal. The digital signal is compressed at the provider and sent to the end user. The "tuner" (which can be built into a tv, a set top box or a cable card) Then decompresses the digital signal and converts it into an analog signal. There is much more to this did not know how technical you wanted your answer.
A Demodulator (MODEM)
Electromagnetic spectrum of radiation
NO
A DSLAM or digital subscriber line access multiplexer is a network device in the telecommunications industry. It receives multiple signals from multiple subscribers DSL connections in order to transfer the signals to the the high-speed network backbone.
DAC
yes its very simple to convert VGA signal into SVGA signal.
modemmo-dem =MOdulatorDEModulator
The brain
to find their ESD and PSD
an encoder is used to convert the binary signals into analog signals. the binary signals are fed to encoder section. then these signals are get converted into its equivalent analog signals. Binary DAC.
a modem
coherent light