This book presents recent and upcoming technological advancements in millimeter-wave (mm-wave), infrared (IR) and terahertz (THz) frequency spectrums. The scope of this book includes a significantly long portion of the electromagnetic spectrum, starting from the mm-waves (i.e. 30 GHz) and extended up to the end of the near-IR spectrum (i.e. 450 THz). Most significant aspect of this portion of the electromagnetic spectrum is that it includes a frequency regime where the gradual technological transition from electronics to photonics occurred. The book especially focuses on the recent...