Showing papers on "Apochromat published in 2019"

Optical performance evaluation and chromatic aberration correction of a focus tunable lens used for 3D microscopy

Abstract: Recently, the development of motion-free 3D microscopy utilizing focus tunable lenses (FTL) has been rapid. However, the downgrade of optical performance due to FTL and its gravity effect are rarely discussed in detail. Also, color dispersion is usually maintained purely depending on the FTL material without further correction. In this manuscript, we provide a quantitative evaluation of the impact of FTL on the optical performance of the microscope. The evaluation is based on both optical ray tracing simulations and lab experiments. In addition, we derive the first order conditions to correct axial color aberration of FTL through its entire power tuning range. Secondary spectrum correction is also possible and an apochromatic motion-free 3D microscope with 2 additional doublets is demonstrated. This study will serve a guidance in utilizing FTL as a motion-free element for 3D microscopy.

Apochromatic lens design in the short-wave infrared band using the Buchdahl dispersion model.

Abstract: Chromatic aberration is an important artifact that influences image quality. Thus, it should be optimized during lens design. However, the typical combination and selection method of glass materials for the visible band can hardly satisfy the apochromatic requirements of short-wave infrared (SWIR) lenses. Therefore, we propose a method of glass selection for apochromatic lens design in the SWIR band through vector operation based on the Buchdahl model and third-order aberration theory. The proposed method overcomes limitations of traditional methods and unstable calculation results of special material properties. A design example is presented, which indicates that the proposed method can correct the secondary spectrum in the SWIR band and simplify the design using ordinary mass-produced glasses.

Three-band apochromatic ultraviolet optical system

Abstract: The invention discloses a three-band apochromatic ultraviolet optical system. The system successively consists of a front lens set G1, a relay lens set G2, a diaphragm front mirror set G3, a diaphragm, a diaphragm rear mirror set G4 and rear mirror set G5 from object space to image space. The system is compact in structure and suitable for scenes such as criminal investigation site searching and photo taking; three-band achromatism of 250-400 nm, 450-660 nm and 700-900 nm can be realized, so that imaging can be more intelligible and sharper; the system has a large aperture, can be used for ultraviolet, visible light and near infrared, and integrates long distance target searching and macro shooting and evidence collecting, so that the excellent quality of imaging can be realized; close-shot distances can be greatly compressed by 100 mm, so that shot images can obtain more detail characteristics; and through the using of quartz and calcium fluoride spherical glass, easy processing can be achieved, and the transmittance in a band range of 250-900 nm is greater than 90%.

Achromatic microscope objective lens

Abstract: The utility model relates to an apochromatic microscope objective (1), which comprises three subsystems (G1, G2 and G3) with at most nine lenses (L1 to L9) in total.

Methods for detecting transmission wavefront with arbitrary wavelength of optical system

Abstract: The invention provides two methods for detecting the transmission wavefront with an arbitrary wavelength of an optical system. On the one hand, four kinds of laser interferometers with the wavelengthsof lambda 1 to lambda 4 are used for detecting an apochromatic optical system and fitting is carried out based on a Zernike polynomial to obtain a transmission wavefront with the wavelength of lambdan of the optical system; and on the other hand, four kinds of detecting devices with the wavelengths of lambda 1 to lambda 4 are used for detecting the optical system and then a complete transmissionwavefront with the wavelength of lambda n of the optical system is obtained according to a discrete point wavefront aberration formula. The two methods can be applied to a single-wavelength system, an achromatic system, and an apochromatic system, thereby solving a problem of wavefront detection with the arbitrary wavelength of the transmissive optical system. Therefore, the detection range of the laser interferometer with the special wavelength becomes large; and when some special optical systems need to be detected, usage of some expensive laser interferometers with the special wavelengthsfor detection is avoided, so that the detection cost is saved.

Apochromatic continuous zooming optical lens with visible light near-infrared broadband

Abstract: The invention relates to an apochromatic continuous zooming optical lens with a visible light near-infrared broadband. The problem of secondary spectrum introduced by the visible light near-infrared broadband is eliminated by use of a reasonable matching method of low dispersion glass and other optical glass to control an optical system color different in a reasonable range; high-definition imaging of the whole zooming section is guaranteed while an optical system length is effectively shortened by use of three groups of linked zooming modes in a mechanical compensation zooming method; diaphragm calibers of zooming positions are guaranteed to be consistent in the whole zooming process by use of a negative vignetting setting method to implement fixed diaphragm caliber variable F number, andmeanwhile the uniformity of relative illuminations of image surfaces at the zooming positions is guaranteed; high-definition images are guaranteed to be provided at day and night in the whole zoomingsection; the cost is reduced since a universal optical glass material and the whole spherical design are adopted, and the optical imaging performance is excellent.