Laser beam scanners are used to modulate the direction of laser light, and are critical components of airborne and space-based LIDAR and optical communications systems. We report here a laser beam steering device design based on dithering two complementary (positive and negative) binary optic microlens arrays. When the two microlenses are translated relative to one another in the plane parallel to their surfaces, a light beam can be scanned and controlled in two directions. The first demonstration of this device concept was reported by Lincoln Laboratory. We have demonstrated a miniaturized version of this concept consisting of a pair of 6-mm-aperture binary optic microlens arrays designed for HeNe laser wavelength.

A mechanical splice has been developed that aligns optical fibers with precision approaching fusion splices. This novel device was made using bulk silicon microfabrication processes and can be cost effectively manufactured. The basic concept can be applied to fiber arrays and active devices.

Various techniques for potential low-cost fabrication of integrated optical devices by hot embossing into polymers are presented. Their advantages and disadvantages concerning fabrication restrictions and thermal properties of final devices are discussed. For two polymers, the long-term dimensional stability of embossed microstructures is investigated. The results show the suitability of this promising low-cost replication technique for practical applications.

Miniature active optical components with micro actuator are developed to miniaturize active optical components and sensors. The piezoelectric micro actuator and the miniature 2-D optical scanner, these are the key devices of the components, and its applications are described in detail.

A micromachined chopper has demonstrated modulation of coherent and incoherent light. The chopper uses an electro-statically driven lateral micromotor to actuate a shutter plate across a through-substrate window. Test devices have been fabricated and exhibit operating frequencies ranging from 1 to 31 kHz and have stable defection amplitudes of 400 micrometers . Further optimizations of the design are discussed.

A unique process has been developed to mold precision plastic optical ferrules using a DuPont proprietary liquid crystal polymer. Optical performance of the plastic ferrules is similar to ceramic ferrules for single mode applications. This paper describes the unique molding process, the polymer system, and the optical performance of this novel plastic ferrule.

A new configuration of three micro-optical elements has been proposed for the realization of miniaturized optical beam deflection and modulation modules: One element with a special surface corrugation profile is placed in the focal plane of two microlenses or microlens arrays, one for focussing the incoming beam(s) and the second for output beam collimation. When the middle element is moved in lateral direction with respect to the optical axis, the parameters of the optical beam(s) is/are influenced depending on the real micro-optic structure. The results of first experiments on optical beam deflection and phase modulation are demonstrated.

This paper reviews our recent progress in the design, fabrication, and performance of Vertical Cavity Surface Emitting Laser (VCSEL) devices and arrays. High power (> 11 mW cw), high speed (10 GHz), high temperature (> 130 degree(s)C) and low voltage (< 2 V) and low threshold current operation are demonstrated. A monolithic spatial filtering technique is implemented for transverse mode control resulting in exceptional optical characteristics. Novel high power 2D coherently-coupled VCSEL arrays emitting over 1 W are discussed. One and two-dimensional individually- and matrix-addressable arrays are demonstrated.

Arrays of two different sizes, each consisting of 16 by 16 blazed Fresnel zone lenses, were fabricated in quartz glass by means of microstructuring techniques. The lenses were designed for free space optical interconnection networks operating in the IR. In order to achieve high diffraction efficiencies the kinoform profile of the microlenses was approximated by a staircase-like profile. The fabrication of the lenses involved multiple steps of repeated pattern transfer by photolithography and successive reactive ion etching. We fabricated Fresnel zone lenses with 16 levels per zone and with different focal lengths. The individual elements of the two arrays have circular and square apertures with a diameter of 2 mm and 200 micrometers respectively and were designed to operate at a wavelength of 1.52 micrometers .

Refractive or diffractive microlenses have already been reported. Here we discuss two examples of microlenses where the generation process and the interferometric control are strongly interwoven. For refractive lenses we use lenses melted in photoresist and also reactive ion etched samples. The control is done with the help of a phase shifting interference microscope of the Mach-Zehnder type. We developed an evaluation software under Windows. The software allows for the evaluation of the wave aberrations and related functions as are psf and otf.

The field of mini- and micro-optics is stimulated by the development of optical fibers and optical systems for communication, cable television, medicine, diode lasers devices, optical disc memory and optical computers, etc. Such variety of the application directions demands a new more variable components base which cannot be realized by the traditional methods of optical technology. We summarize current theories of physical essence and technical opportunities of different laser technologies for MOC fabrication.

We have designed two types of interferometers without moving parts, one is of the Michelson type, the other of the lamellar grating type. For both, the incident wavefront is divided into 2ⁿ parts, and each part produces one signal point for an interferogram, which can be Fourier transformed to give the desired spectrum. The 2ⁿ parts operate like an array of interferometers and since all points of the interferogram are instantly available, real time resolved spectroscopy may be performed.

We propose an integrated optical polarization detection device for magneto-optical disk pickups. The device has a prism coupler and a TE/TM mode splitter which is monolithically integrated on a silicon substrate with p-i-n photodiodes and two optical waveguides with different effective indices of refraction. These two waveguides are connected at two tapered transition regions. This paper describes the device fabrication techniques and the performance of each element integrated in the device. The optical waveguide TE/TM mode splitter is shown to have wide tolerance for wavelength change, fabrication error, or deviation from designed incident angle.

Deep etch lithography of PMMA by proton lithography is a powerful tool for the fabrication of monolithically integrated fully refractive microlenses, microprisms, and microbeamsplitters. This technique can be applied to many applications in the field of free space optical interconnects.

The wide facilities of optical components forming using the methods of laser treatment of the optical glass and glass-like materials attract attention of many investigators nowadays 1,2,3 Local laser heating controlled in area and time allows to get the materials with a new non-equilibrium structure having the different values of density p and, consequently, the different values of refraction index (RI) ii. RI distribution ti(r) in glass and gi ass-like materials ( mean ceramics,glass-ceramics etc.) defines by the temperature distribution Tfr) , the values of heating and cooling rates in the laser treatment zone (LTZ) and also depends on the physical and thermomechanical properties of sample and its "thermal history".While controffing by laser intensity distribution q(r, t) in the LTZ, by the time of laser action -r and the temperature of preliminary heating of sample T0 we are able to form a different distributions of RI in the local volumes of glass and to control by the surface profile of sample in and near the LIZ.

The trend towards smaller design geometries for microelectronics devices places unprecedented demands on the measurement of these small structures. Two sample problems are considered. In the first case we predict the shape of developed photoresist gratings from diffraction data obtained from an angle scanning scatterometer in which a detector tracks a particular diffraction order as the angle of incidence is varied. The second problem we consider is the prediction of depths of cylindrical cells etched into Silicon. A dome scatterometer is used to collect the 2-D diffraction signal and in this case the experimental data is used to construct a data base of scatter signals.

An exact model for chirped binary gratings is introduced together with an analytic solution applicable in the electromagnetic regime. The solution employs a multiple scattering matrix formulation and boundary value problem techniques to determine the scattering coefficients of the diffracted fields, which in turn leads to an iterative algorithm for grating designs. Numerical examples on the design of a binary grating lens operating in the near-field are presented with computer simulations. It shows that under oblique plane wave illumination more than 90 percent of the diffracted power can be focused into a narrow beam of one wavelength in beamwidth over the image plane which is located only 12 wavelengths away from the grating plane.

Polarization sensitive diffractive optical elements are useful for free space optical interconnection networks and packaging. We demonstrate a multi-phase level polarization selective computer generated hologram with independent functionality for two orthogonal linear polarizations using lithium niobate substrate. The adjustments for design and fabrication of such an element are shown in this paper.

Miniature optical systems utilizing arrays of lenses had been conceived by the early part of this century. More recent uses for multi-aperture optics have included Hartmann wavefront sensing and agile beam steering. To support our own research efforts in micro-optics Adaptive Optics Associates, Inc. developed first-order raytrace software that is capable of modeling multi-aperture systems. The graphical user interface at the heart of this software gives a CAD- like utility to the program, which is a powerful tool for the micro-optics design engineer. The article discusses the benefits of such an interface. Several examples of micro-optics systems taken from available literature are analyzed.

Microlenses and microlens arrays present challenging measurement problems to manufacturer and user alike. Standard techniques designed for testing larger optical components are impractical for lenses with dimensions of only a few hundred micrometers. We present several methods for characterizing the wavefront, focal length, surface profile, and other parameters of microlenses and microlens arrays. The use of Mach-Zehnder and Twyman-Green interferometers for wavefront and focal length measurement are discussed in some detail.

Dielectric corrugated waveguides are used in DFB and DBR lasers. Coupled mode theory is used to study the effect of variations in grating shape on the performance of DFB and DBR lasers. The purpose of this paper is to find the optimum geometry for different applications.

A method to compute diffractive elements focusing in a set of lines located in different focal planes along the optical axis is considered. A phase nonlinearity is applied to the phase function of a focusator in a line. It is proven that the selection of the nonlinearity is reduced to the problem of the phase diffraction grating with pre-set energy distribution in the orders. Combined multi-focal elements to focus in two sets of lines simultaneously are considered as well; the first consists of lines located in one plane and the second of lines located in different focal planes along the optical axis.

The process of forming cylindrical glass microlenses drawn from a precisely shaped preform provides optical engineers and designers a novel source of miniaturized optical components with very high numerical aperture and diffraction-limited performance. Because of these characteristics, and because of the inherent anamorphic nature of cylindrical optics, drawn microlenses are ideally suited for use with most laser diodes. The technology has evolved during the past couple of years to the point that laser diodes products incorporating these microlenses are now available commercially, and they are beginning to be incorporated into commercial instruments. In this paper we review the current status of drawn cylindrical microlenses, and discuss some novel applications being developed.

Three-dimensional integral imaging and display systems, employing optical arrangements, require efficient large aperture transmission elements. The employment of two tier optics in conjunction with microlens focusing screens and two tier imaging combinations provide these and in parallel retain the angular and lateral resolution required. The properties of superlens combinations and their use for the control of axial magnification in 3-D spatial imaging is described. Attention is drawn to the advantage of using segmented lens forms due to their capacity to achieve a scaled image suitable for electronic or photographic capture.

Technological possibilities of making wide-angle micro-objectives for endoscopes out of separate modules with different refractive indexes (RI) have been considered and the corresponding investigation of optical calculations has been done. Aspherical surfaces in modules was achieved without any mechanical treatment.

This paper discusses the effects of an etching process on the optical figure of a microlens transferred from photoresist to an underlying substrate. I state a general equation for the evolution of a surface under etching conditions. I then show how isotropic and anisotropic etching conditions behave within this surface evolution theory. I demonstrate how ion milling is not an anisotropic process when eroding 3-D surfaces. Finally, I show that this behavior leads to aberrations in microlenses when subjected to ion milling as a pattern transfer technique.

Refractive microlenses are fabricated by the P²ROM (Preshaped Photoresist Refractive Optics by Melting) process. A polar coordinate HeCd laser beam lithography system (laser writer) is used to directly expose a continuous spheroidal profile into photoresist to fabricate 200 micrometers diameter microlenses with speeds between F/1.5 and F/5. Interferometric surface measurements, used to determine optical quality of the preshaped microlenses, indicate reduced spherical aberration in slow lenses fabricated by this method.

Reactive ion etching (RIE) is used to fabricate infrared refractive micro-optics in silicon. Three methods are used: binary optics technology which uses iterative steps of photolithography and RIE to create a multistep approximation to an aspheric profile; direct etching of a preshaped polymer microlens etch mask into the substrate; and analog etching of a lens profile directly into the substrate through a pinhole mask.

A new approach is developed in research of optical image structure. This presentation describes the methods and devices for definition of point spread function (PSF) quantities in the superwide range of measurable illuminations (100,000 times). Precision of evaluations of modulation transfer function (MTF) and energy concentration is increased. Examination and display of the map of PSF is fulfilled in real time. We discuss the conditions under which such improvement may be possible.

Problems of microelectronics technology applications for diffractive optical elements fabrication have been considered. The results on x-ray diffractive focusing elements are described: amplitude and phase-contrast Fresnel zone plates as well as freestanding gold gratings. The creation of reflected Bragg-Fresnel lenses for soft x-ray range was made on the basis of multilayer x-ray mirrors. Considerable attention was paid to the correction of different distortion factors involved in the electron beam lithography process.

Integrated Optics on Silicon substrate (IOS) has appeared very early. This original work was concerned with monolithic integration of waveguides and photodiodes which seemed then to be THE major advantage of silicon. Since these pioneer times, a lot of work has been done and new reasons for the world-wide success of silicon have emerged. We try in the following paper to make a short overview of the possibilities offered by silicon, along with new trends appearing on IOS, each of them trying to overcome the limitation of IOS to passive devices.