Sem 2

Computer Engineering

Year 1

First Year

`Unit – 4Photo DetectorsQuestions And Answer 1) What are the three main types of Photo detectors?Answer:The three main types of Photo detectors are:      Photoconductors junction       Photodetectors       Avalanche photodiodePhotodetectors: a photodetector is an optoelectric device that absorbs optical energy and change it to electrical energy, which usually obvious as a photo current                        [<img alt="" height="22" src="https://glossaread-contain.s3.ap-south-1.amazonaws.com/epub/1714210202_9819875.png" width="456"/> 2) Explain PIN Photodiode.<div style="margin-left:18pt; background-color:#ffffff">      The PIN photo diode operates with an realistic reverse bias voltageand when the reverse bias is applied, the space charge region must cover the intrinsic region totally. </div><div style="margin-left:18pt; background-color:#ffffff">      Electron hole pairs are generated in the space charge region by photon absorption. </div><div style="margin-left:18pt; background-color:#ffffff">      The swapping speed of frequency response of photodiode is inversely proportional to the life time.</div><img alt="" height="187" src="https://glossaread-contain.s3.ap-south-1.amazonaws.com/epub/1714210203_0548148.png" width="448"/> 3) Explain Avalanche Photodiode.`

`<h3 id="navPoint_1" style="margin-top:0pt; margin-bottom:11.25pt; line-height:16.8pt; background-color:#ffffff">Avalanche photo diode is a sympathetic of photo detector which can convert signals into electrical signals. The overhead figure is of Avalanche Photodiode. Avalanche photodiodes are used in applications where very sensitive light detection is required.</h3><h3 style="margin-top:0pt; margin-bottom:11.25pt; line-height:16.8pt; background-color:#ffffff"> </h3>`