Measurements using Optic and RF Waves

Chapter 2From Measurement to Control ofElectromagnetic Waves using a Near-fieldScanning Optical Microscope¹

 

 

 

2.1. Introduction

The development and achievement of increasingly smaller components imposes the control of the electromagnetic field distribution on the required scales. By confining light in increasingly smaller volumes, the local amplification of the confined electromagnetic field is accompanied by a very high sensitivity of the components to the external environment.

Measurement of the electromagnetic field in structures of subwavelength size remains today a field of open application. We will present in this chapter some examples of these problems of local optical measurement, which as we will indicate finds its limits as a measurement, because on these largely subwavelength scales, the measurement can modify the properties of that which is measured.

First, we will describe the principle of local probe microscopy, limiting our description to the collection mode. We will discuss what the probe actually measures: field, intensity, etc. The measurement of the near-field in the vicinity of a surface with a random roughness will be presented. Then we will approach the measurements relating to the near-field study of integrated optic components. After the near-field characterization of photonic crystal components, a near-field measurement technique, which provides access to the amplitude and the phase of the measured signal, will be presented. Finally, the last part of ...