Diode lasers are becoming increasingly important in length metrology. We demonstrate construction of a simple single-frequency diode laser 632,8 nm, used as a frequency standard in the laser interferometers. We present two different systems applied for frequency stabilization of diode laser . For diode laser used as the secondary standard, the system stabilizes diode temperature, the frequency stability of the laser reaches value 1 part in 10⁶. For diode laser used as the primary standard is developed stabilization system using narrow absorption in iodine , the frequency stability of constructed diode laser reaches value 1 part in 10¹⁰.

An optical differentiation phase measurement system using a modified multi-step bias-shifting method is proposed. The signal obtained by multi-step bias shifting is divided into two groups in this new method. The effectiveness of the new method was demonstrated using a computer simulation.

A fast optical roughness measuring device with a compact design is presented. The measuring principle is based on double scattering of coherent light. The measurement results in an integral statistical roughness value like Ra or Rq according to ISO 4287. It is valid for the illuminated surface area with diameters between 0.5 mm and 10 mm at a resolution of about 1 nm (Ra-value). A simulation model of the optical roughness measuring process based on the Huygens-Fresnel approximation was implemented. The simulation tool enables to investigate potential improvements of the measuring method without expensive and time consuming experiments.

In this paper, we report on the recent development of a novel low coherence interferometry technique for the purpose of 3D-topography measurements. It combines the well established techniques of spectral-interferometry (SI) and chromatic-confocal microscopy (CCM). It allows for the detection of an object’s depth position, without the necessity of a mechanical axial-scan, and the measurement is performed in a so-called “single-shot” manner. Focusing the white-light with a microscope objective combined with a diffractive optical element leads to an expansion of the axial-range of the sensor beyond the depth-of-focus, limited by the numerical aperture (NA) of the used objective. Confocally filtering the object’s light causes the reduction of the lateral dimension of the area sampled upon the object. Due to the high NA, a high light collection-efficiency is achieved as well. The attained interferometric signals consist of high-contrast wavelets in the optical-frequency domain. The depth position of an investigated point of the object is given by the modulation-period of the wavelets. Therefore, unlike in CCM, position-wavelength referencing is not necessary.

We propose a super-resolution microscopy that employs standing evanescent light illumination and image reconstruction method with successive approximation. Samples are illuminated with standing evanescent light, which is formed and shifted into different positions on the interface of total internal reflection (TIR). Scattering light emitted from the illuminated samples is detected through far-field imaging optics. We assume two hypotheses of linearity and incoherence about the scattering light. Then we reconstruct the sample distribution from scattering images and standing evanescent light intensity with successive approximation. We examined this microscopy with one-dimensional computer simulation and demonstrated that super resolution over the diffraction limit is achievable. The resolution power improves with shorter peak-to-peak distance of standing evanescent light and more cycles of the reconstruction calculation. As a possible resolution, two dot samples separated by 50 nm were resolved when the wavelength is 633 nm and the diffraction limit is 594 nm. With two-dimensional computer simulation, we were also able to resolve random dot samples in super resolution by using longitudinal and transversal standing evanescent light.