Method and device for measuring phase delay spectral characteristic of wave plate

Abstract

The invention discloses a method and a device for measuring a phase delay spectral characteristic of a wave plate, comprising a broadband light source; and continuously emergent light is received after passing through a multi-wavelength photoelectric detector through a collimator, a polarizer, two wave plates to be detected, a polarization analyzer and an optical splitter respectively, wherein the two wave plates to be detected are connected with a motor, data received by the multi-wavelength photoelectric detector are uploaded to a data acquisition card which transmits the data to a computer which is connected with the motor. The method disclosed by the invention can automatically measure the phase delay spectral characteristics of the two wave plates to be detected within a wide spectral range, not only can be used for measuring the phase delay spectral characteristics of two rotary wave plates in a rotating double-compensator type broad-spectrum ellipsometer so as to eliminate system errors caused by inaccurate calibration, but also can be used for directly calibrating the phase delay spectral characteristics of two unknown wave plates in practical production and research work, and besides, the measurement result is not influenced by the light source and the spectral characteristic of a detector.

Description

technical field [0001] The invention belongs to the field of polarization optical detection, in particular to a method and device for measuring the phase delay spectrum characteristic of a wave plate. Background technique [0002] Waveplates are often used as devices for transforming the polarization state of optical signals in ellipsometry or optical measurements. The phase delay error of the wave plate will have a great impact on the measurement results. Therefore, in the process of making and using the wave plate, it is often necessary to accurately measure the phase retardation spectral characteristics of the wave plate. For example, in the rotating double compensator type broad-spectrum ellipsometer (PCSCA type ellipsometer), the precise calibration of the delays of the two compensators C1 and C2 is the premise of high-precision measurement. The working wavelength of the two rotating compensators Range has a significant impact on overall machine characteristics. [0...

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Problems solved by technology

[0005] However, this solution is limited by the measurement wavelength range of the Fourier transform analyzer used (this instrument is usually used in the infrared band), there are many error sources and the solution process is relatively complicated

Of course, other instruments (such as other commercial ellipsometers) can also be used to measure the two compensators of the rotating double compensator ellipsometer separately, and then assemble them. The biggest problem with this solution is the phase delay of the compensators. The spectral properties are limited by the measuring spectral range of the ellipsometer used and the process is more complex

[0006] There are many methods for measuring wave plate phase retardation, but they are often only suitable for measuring the wave plate phase retardation at a specific monochromatic wavelength, and cannot simultaneously measure the phase retardation spectral characteristics of wave plates in the case of multiple wavelengths

And some measurement methods can, but can only measure the phase delay spectral characteristics of a single wave plate, and cannot simultaneously measure the phase delay spectral characteristics of two wave plates to be tested

[0007] Although Chinese patents CN1743796 and CN100340838C can read the measurement data of multiple wavelengths at one time, they cannot simultaneously measure the phase delay spectral characteristics of two wave plates

[0008] The methods of Chinese patents CN1632501, CN201032473Y and CN102589850A also need to select a single wavelength each time through the monochromator to measure the characteristics of a single wave plate to be tested, which is more limited in the occasions requiring easy operability and measurement speed.

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