Mach-Zehnder interferometric sensors

Interferometric sensors frequently have also been applied to biosensor measurements. Thereby, the evanescent field technique (Mach-Zehnder interferometer) has been compared with other optical detection principles regarding information on layer structure and in case of biosensing30. The... 

Fig. 7.17 Principle of fiber core cladding mode interferometric (CCMI) sensors (a) Mach Zehnder type and (b) Michelson type...

One of the main advantages of the optical-based sensors is their high resolution. Integrated optical sensors16, especially the interferometric ones that have been developed in recent years, such as the Mach-Zehnder interferometer (MZI)17 and the Young interferometer 18-21, show an extremely high refractive index resolution in the range of 10 1—10 8 RIU (refractive index units)17,21, which is equivalent to... 

Alternatives to the presented interferometric configuration are Mach-Zehnder-type interferometers that are also available as integrated optical devices the performance of such optical sensors will be tested for the above application in the near future. 

Many types of interferometry can be used for this purpose. For instance, the Twyman-Green interferometer [11] is suitable for surface testing in reflection. The Mach-Zehnder interferometer permits lens testing in transmission [12]. The third interferometric technique utilizes a Shack-Hartmann wave-front sensor [10,13,14]. This method can be applied to both reflection and transmission. Interestingly, the Shack-Hartmaim sensor utilizes a microlens array in front of a CCD imager array to create a series of focal spots that are recorded by the CCD imager to obtain the wavefront. 

Measurement by interferometric sensors with Mach-Zehnder interferometer. 

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