A temperature-tunable etalon for optical telecommunication wavelength: Difference between revisions

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Suppose that the a_1, a_2, a_3 are the light intensity of input, oscillating, output light.  
Suppose that the a_1, a_2, a_3 are the light intensity of input, oscillating, output light.  


Suppose the gap between two reflective surfaces is d and the refractive index in the cavity is n_e.
Where the gap between two reflective surfaces is d and the refractive index in the cavity is n_e.


==Building an Etalon Out of Silicon Wafer==
==Building an Etalon Out of Silicon Wafer==

Revision as of 16:01, 16 February 2021

Members

Shi Yicheng (A0054800R), Du Jinyi (A0227185B), Zhang Qian(A0228752Y)

Rationale

A Fabry-Perot interferometer (or an Etalon), being probably the simplest form of all interferometers, is found useful in a variety of optical applications such as spectral filtering or frequency referencing.

An etalon is typically constructed out of the two parallel reflecting surfaces of a transparent plate. The plate needs to have low absorption loss for the desired working wavelengths to ensure a relatively high finesse of the etalon. The material choice for visible wavelengths is usually fused silica with an absorption coefficient of [bla] and a thermal expansion coefficient of [bla].

For optical telecommunication wavelengths, which range from about 1260nm to 1625nm, pure silicon becomes a more practical choice with an absorption coefficient of [bla] and thermal expansion coefficient of [bla].

Characteristic Parameters of an Etalon

The performance of etalon is characterized by several main parameters: including visibility (V), free spectral range (FSR), full width half maximum (FWHM), and central wavelength.

Suppose that the a_1, a_2, a_3 are the light intensity of input, oscillating, output light.

Where the gap between two reflective surfaces is d and the refractive index in the cavity is n_e.

Building an Etalon Out of Silicon Wafer

Design

(this section will stay empty for a long time...)

Performance

caption

Bare Silicon Wafer

Transmission spectrum of a bare silicon wafer of 100μm Zoom in of the spectrum, showing a free spectral range of ~2.3nm (~400GHz)

HR Coated Silicon Wafer

Temperature Tuning of silicon etalon