Abstract: Disclosed is a Photonic Phase Locked Loop (PPLL) detector/discriminator, which makes possible a system for optically transmitting electromagnetic signals through a transmission medium (such as optical fiber, optical waveguide, underwater, in biological tissue, or in free space) with high sensitivity and extremely high dynamic range exceeding what is possible with present optical intensity modulated (AM) systems. Information is encoded on an optical carrier through the use of phase modulation (PM) or frequency modulation (FM). This information is subsequently demodulated into an accessible form through the use of the PPLL.

Abstract: A chirp signal source includes first and second lasers formed on a solid-state chip or substrate. Each of the lasers has a resonator or cavity which incorporates or includes electrooptic material which changes refractive index in response to an electric field. The lasers are pumped, and the resulting laser beams are coupled to a light-to-electric converter which combines the light beams to generate an electrical difference frequency. The change in refractive index allows the lasers to be swept or chin,ed at a much higher rate than thermal or piezoelectrically operated lasers. This structure has the advantages of tending to reduce temperature effects on the difference frequency. It has the further advantage of a high sweep rate, which can be used to improve the signal-to-noise ratio. A radar or lidar ranging system according to an aspect of the invention uses multiple solid-state lasers, which are thermally coupled together.

Abstract: Informational data is efficiently recorded on a recording medium in response to an input signal containing information and pauses of different intervals. Information following each pause is captured for recording and space occupied on the recording medium for recording of the pauses is minimized. A stream of input data corresponding to the input signal is supplied by operation of a controller selectively to a first buffer and a second buffer arrangement. The input signal is also coupled to a record signal generating circuit that produces a record signal in response to an input signal having information of a certain duration, and produces a no-record signal in response to a pause in the input signal of a determined interval.

Abstract: A method of evaluating designated responses to a series of questions includes the steps of forming on a surface of a markable sheet a number of response mark guides, whereby responses to the questions can be designated by placing marks on or within selected ones of the response mark guides. The response mark guides are arranged at certain positions on the sheet to define arrays of a certain reference form, e.g., a clock face, and each of the response mark guides of each array is associated with a different possible response such as a number from 0 to 9, according to the reference form. Responses are evaluated by interpreting the marks in accordance with their positions as placed on or within the response mark guides of the arrays and according to a selected response key.

Abstract: An answer recording and score sheet device includes a markable sheet arrangement with at least one surface that has answer mark guide indicia. The guide indicia define sets of first positions at which marks can be selectively made by a respondent in response to corresponding questions. The sheet arrangement also has a surface on which a number of discriminable flag indicia are formed in a determined relation with respect to the first positions. The flag indicia serve to convey correct responses in accordance with a given test form or answer key, and are of such form as to enable rapid manual or electronic grading of the chosen responses.

Abstract: An apparatus and process for separating the pith from the bast of sweet sorghum is disclosed. Cut and headed stalks of the plant are arranged as a mat of the required width on a conveyor and are forcibly advanced endwise into a rotating flail having a multiplicity of dull beating or striking elements which catch the advancing stalks against a stationary bar. The output of the process is a hail of small discrete particles of wet sugar-laden pith used in the production of fuel alcohol and elongated strings of fibre which had been the organized structural backbone of the plant. The quite differently sized and shaped products are separated by vibrating screens or elutriation in an air stream.