Light field displays comprise three-dimensional (3D) visual information presentation devices capable of providing realistic and full parallax autostereoscopic images. In this letter, the recent advances in the light field displays based on integral imaging (II) and holographic techniques are presented. Several advanced approaches to demonstrate the light field displays including viewing angle enhancement techniques of the II display, a fast hologram generation method using graphics processing unit (GPU) and multiple WRPs, and a holographic microscopy to display the living cells are reported. These methods improve some important constraints of the light field displays and add new features.

We propose an automatic three-dimensional (3D) pupil tracking backlight system for holographic 3D display system with large image size and full-parallax accommodation effect. The proposed tracking module is applied to a holographic 3D display system with two sets of directional holographic imaging module composed of 2×2 large scale lens array and 22-inch high-resolution liquid crystal display 3D panel. System architecture is described and experimental results are presented.

A multiplexed holographic display video has been achieved by using a passive azo-dye-doped liquid crystal (LC) cell. Holograms formed in this cell can be refreshed in the order of several milliseconds. By angular multiplexing technique, dynamically multiplexed holographic videos are realized. Moreover, the reconstructed RGB images are merged into a color image, which illustrates the possibility of a color holographic three-dimensional (3D) display by holographic multiplexing of the LC cell.

Multiple three-dimensional (3D) display technologies are reviewed. The display mechanisms discussed in this paper are classified into two categories: holographic display in wave optics and light field display in ray optics, which present the 3D optical wave field in two different ways. Key technical characteristics of the optical systems and the depth cues of human visual system are analyzed. It is to be expected that these 3D display technologies will achieve practical applications with the increase of the optical system bandwidth.

We propose a new optical profilometer for three-dimensional (3D) surface profile measurement in real time. The deviation angle is based on geometrical optics and is proportional to the apex angle of a test plate. Measuring the reflectivity of a parallelogram prism allows detection of the deviation angle when the beam is incident at the nearby critical angle. The reflectivity is inversely proportional to the deviation angle and proportional to the apex angle and surface height. We use a charge-coupled device (CCD) camera at the image plane to capture the reflectivity profile and obtain the 3D surface profile directly.

Plasma ion-assisted deposition (PIAD) process for ultraviolet (UV)-induced transmission and full dielectric thin-film filters in the 200–400 nm spectral region is described. The design and manufacturing method of the UV filters are introduced. The UV filters exhibit deep blocking (> optical density (OD)5–OD6), high transmittance, and stable environment durability. These UV filters pass 10 cycles in an aggravated temperature-humidity test, according to ISO9022-2 and MIL-STD-810F standards.

Antireflection coatings are very important for high-efficiency solar cells. An ideal antireflection structure should lead to zero reflection loss on solar-cell surfaces over an extended solar spectral range for all angles of incidence. Based on the optical thin-film theory, two multilayer structures are adopted as initial stacks in two conditions, respectively. With the aid of a conjugate graduate optimized method, the incident angles of antireflection coating are 0°–60°, the working wavelength range is 400–1200 nm, and two broadband and wide-angle antireflections are designed. The results show that they can all evidently reduce residual reflection.

We present the advantages of experimental design in the sensitivity analysis of optical coatings with a high number of layers by limited numbers of runs of the code. This methodology is effective in studying the uncertainties propagation, and to qualify the interactions between the layers. The results are illustrated by various types of filters and by the influence of two monitoring techniques on filter quality. The sensitivity analysis by experimental design of optical coatings is useful to assess the potential robustness of filters and give clues to study complex optronic systems.

Total loss test of the high-reflective (HR) film coated on super-smooth silica substrate by dual ion beam sputtering (DIBS) is based on the well-established cavity ring-down technique. Scattering and transmittance are tested by integral scattering and transmittance measuring apparatus, after which absorption is calculated. At 632.8 nm wavelength, the magnitude and distribution of thin film loss are researched for both s- and p-polarization, and the reflectivities are 0.99986, 0.99997, and 0.99962, respectively. Based on the analysis, the tested scattering is less than its real value.

In order to improve the performance of reflectance diffuse optical imaging (rDOI), a novel polynomial geometry (PG) of optical fibers arrangement is proposed. Polynomial geometry is based on the hexagonal geometry (HG) and multicentered double-density (MD) mode. The overlapping sensitivity matrix, area ratio (AR), reconstruction image, two-absorber model, and contrast-to-noise ratio (CNR) in different depths are used to evaluate the performance of PG. The other three geometries including HG, rectangular geometry (RG), and MD mode are also compared with PG. The deformation of the reconstruction images is evaluted by circular ratio (CR). The results prove that the proposed PG has high performance and minimum deformation in quality of reconstruction image in rDOI.

A simple all optical system for stopping and storing light pulses is demonstrated. The system consists of an erbium-doped fiber amplifier (EDFA), a semiconductor optical amplifier (SOA), and a fiber ring resonator. The results show that the multisoliton generation with a free spectrum range of 2.4 nm and a pulse spectral width of 0.96 nm is achieved. The memory time of 15 min and the maximum soliton output power of 5.94 dBm are noted, respectively. This means that light pulses can be trapped, i.e., stopped optically within the fiber ring resonator.

A novel composite model is put forward for humidity-sensitive material based on Maxwell-Garnett and effective medium theory. The analytical expression of the relation between effective refractive index and relative humidity is shown with different absorption factors and porosities. The larger the absorption factor is, the higher the refractive index is. The refractive index of humidity-sensitive SiO<sub>2</sub> film decreases with the increase of ceramic material porosity. The sensitivity of optical humidity sensor can reach the magnitude of 10<sup>?3</sup>. In comparison with the experimental humidity-sensing curve by the method of p-polarized reflectance and the analysis of mechanism, theoretical simulation is in agreement with experimental results. Therefore, this composite model is proved to be reasonable which lays new theoretical foundation in further research on optical humidity sensor.

An approach, based on the correlation between the intensity distribution of object wave of the directly recorded by charge-coupled device and the one reconstructed by computer, is proposed to evaluate the quality of the phase reconstruction in light emitting diode (LED) based phase-shifting digital holography. This method enables us to find out the optimal reconstructed phase even though the peak wavelength of LED, which is used for calibrating the phase-shifter, is inconvenient to be determined and tends to shift with temperature and driving current. The feasibility of this method is verified by both computer simulations and experiments.

We report the high speed scanning submicronic microscopy (SSM) using a low cost polymer microlens integrated at the extremity of an optical fiber. These microlenses are fabricated by a free-radical photopolymerization method. Using a polymer microlens with a radius of curvature of 250 nm, a sub-micrometric gold pattern is imaged experimentally by SSM. Different distances between the tip and the sample are used with a high scanning speed of 200 cm/s. In particular, metallic absorption contrasts are described with an optical spatial resolution of 250 nm at the wavelength of 532 nm. Moreover, finite-difference time-domain (FDTD) simulations concerning the focal lengths of microlenses with different geometries and heights support the experimental data.