JPS59165527A - Gas cell type atomic oscillator - Google Patents

Abstract

PURPOSE:To miniaturize a gas cell type atomic oscillator providing with high performance and high reliability by controlling the electric power of a light source lamp driver in response to the output of a photodetector and therefore controlling the temperature of a container of the light source lamp. CONSTITUTION:The output level of a photodetector 3 is set at 0V when the discharge of a light source lamp is started, and therefore the electric power of a lamp driver 7' exceeds a level needed for start of the discharge of the lamp 4. Thus the discharge and emission of light starts for the lamp 4. The light quantity of the lamp 4 increases as the temperature of a lamp house 5 rises up owing to the collector loss of an oscillating transistor 13 of the driver 7'. The electric power of the driver 7' is controlled so as to obtain a fixed level of difference voltage between the output level of the detector 3 compared by a comparator 14 and the set reference voltage so that the light quantity is set at a fixed level when the output level of the detector 3 reaches the set reference level. At the same time, the temperature of the house 5 is also controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a gas cell type atomic oscillator, which is small in size, high in performance, and highly reliable.

(b) Background of the technology The gas cell type atomic resonator is a highly stable oscillator that controls the frequency of the crystal oscillator based on the resonance frequency of atoms, and has excellent long-term frequency stability, so it is used as the reference frequency for communication, broadcasting, measurement, etc. It is used as a compliment.

(c) Prior Art and Problems FIG. 1 is a block diagram showing the circuit configuration of a conventional gas cell type atomic oscillator.

In the figure, 1 is a resonant cell, 2 is a cavity resonator, and the figure shows a cross section, 3 is a photodetector, 4 is a light source lamp, and 5 is a light source rung housing (hereinafter referred to as a lamp house). In the cross section, 6 is a heater, 7 is a lamp exciter, 8 is a temperature controller, 9 is an atomic resonator, 10 is a servo circuit, 11 is a vacuum controlled crystal oscillator, and 12 is a frequency synthesizer.

The atomic resonator 9, which is the central part of the gas cell type atomic oscillator, includes a resonance cell 1, a cavity resonator 2, a photodetector 3, a light source lamp 4,
It is composed of a lamp house 5, a heater 6, a lamp exciter 7, a temperature controller 8, etc., and the light source lamp 4 is a Langhaus 51.
The temperature is about 100℃ due to the heater 6 and temperature controller 8.
The lamp exciter 7f is excited to emit high-frequency discharge light. The light from the light source lamp 4 enters the resonance cell 11, and the amount of light transmitted through this is detected by the photodetector 3.
reach. - The output of the city voltage controlled crystal oscillator 11 is frequency synthesized by the frequency synthesizer 12 and the microwave frequency f
When the x signal reaches the p1 cavity resonator 2I and matches the atomic resonance frequency, atomic resonance occurs within the resonance cell 1 and the amount of transmitted light decreases rapidly.

The photodetector 3 detects this reduced optical signal, and the frequency of the voltage-controlled crystal oscillator 11 is automatically IF-controlled by the length-bo circuit 10 so that the microwave frequency fx matches the atomic resonance frequency. The output of the voltage controlled crystal oscillator 11, which is controlled in this manner, is used as the output of the gas cell type atomic oscillator.

Generally speaking, when the source lamp 4 starts discharging, a larger amount of electric power is required than when maintaining the discharge once it has started. For this reason, conventionally, the light source lamp 4 is excited by the lamp exciter 7 with enough power to start discharging even after the start of discharge, or the light source lamp 4 is excited by the power of the lamp exciter 7 which does not start the discharge by itself. A method has been used in which a high voltage pulse is forcibly applied to the light source lamp 41 to start discharging.

However, in the former method, the excitation power of the light source lamp 4 is large, which deteriorates the long-term frequency stability and frequency temperature characteristics of the gas cell type atomic oscillator. However, the latter method requires a high-voltage pulse generating circuit and is large in size, and both require a temperature controller 8 and are large in size.

(dl) Purpose of the Invention In view of the above-mentioned drawbacks, the purpose of the present invention is to provide a gas cell type atomic oscillator that can be made smaller, more efficient, and more reliable.

(e) Structure of the Invention In order to achieve the above object, the present invention provides a means for controlling the power of a light source lamp exciter according to the output of a photodetector, and a means for controlling the power of a lamp house using the power of the light source lamp exciter. Equipped with means for controlling temperature, temperature controller high pressure pulse generation circuit (
Moreover, when the light source lamp starts discharging, the output level of the photodetector is zero and the level is 3-3. The lamp exciter power and the temperature of the lamp house are controlled so that as the temperature of the p lamp house rises due to the excitation power, the lamp source increases, and after reaching a reference value, the lamp source remains constant. shall be.

Embodiment of the Invention Hereinafter, one embodiment of the present invention will be explained according to the drawings.Second
The figure is a block diagram of a gas cell type atomic oscillator according to an embodiment of the present invention.

Components in the figure that have the same functions as those in FIG. 1 are indicated by the same symbols: 13 is an oscillation transistor, 14 is a comparator circuit, 7' is a lamp exciter, 9' is an atomic resonator, and ■ is a reference voltage.

In FIG. 2, an oscillation transistor 13 for exciting a light source lamp 4 of a lamp exciter 7' whose power is controlled according to the output of a photodetector 3 is thermally coupled to a lamp house 5, and The lamp house 5 is heated using collector loss. That is, the output level of the photodetector 3 and the set reference voltage V are compared by the comparator 134-, and the power of the lamp exciter 7' is controlled at the same time so that the differential voltage becomes constant. Since the output level of the photodetector 3 is zero volts when the light source rung 4 starts discharging, the power of the lamp exciter 7' increases beyond the value required to start the discharge, and the light source lamp 4 starts discharging. Light emission begins.

The temperature of the lamp house 5 rises due to the collector loss of the oscillation transistor 13 of the lamp exciter 7' (as a result, the light intensity of the light source lamp 4 increases and the output level of the photodetector 3 reaches the set reference value). The lamp exciter 7' is operated so that the difference voltage between the output level of the photodetector 3 compared by the comparator 14 and the set reference voltage V is constant so that the amount of light is constant.
At the same time, the temperature of the lamp house 5 is also controlled.

The other operations are the same as in the case of FIG.

By doing so, a temperature control circuit and a high-pressure pulse generation circuit are no longer required, so that the configuration of the gas cell type atomic oscillator can be significantly simplified and downsized.

In addition, since the lamp excitation power is controlled to be large only at startup and small during normal operation, the long-term frequency stability and frequency temperature characteristics of the gas cell type atomic oscillator are good, and the life of the light source lamp 4 is long, making it possible to achieve high performance and high reliability.

(g) Effects of the Invention As explained in detail above, the present invention has the effect of providing a gas cell type atomic oscillator that can be made smaller, more performant, and more reliable.

[Brief explanation of drawings]

Figure 1 is a block diagram of a conventional gas cell type atomic oscillator.
FIG. 2 is a block diagram of a gas cell type atomic oscillator according to an embodiment of the present invention. In the figure, 1 is a resonant cell, 2 is a cavity resonator, 3 is a photodetector, and 4
is a light source lamp, 5 is a light source lamp container, 6 is a heater, 7
, 7' is a lamp exciter, 8 is a temperature controller, 9.9' is an atomic resonator, IO is a servo circuit, 11 is a voltage-controlled crystal oscillator, 12 is a frequency synthesizer, 13 is an oscillation transistor, 14 is a Comparator, ■ indicates the reference voltage. 7- 1IJ Figure 2

Claims (1)

[Claims] The oscillator ζ2 is provided with means for controlling the power of the light source lamp exciter and means for controlling the temperature of the light source lamp housing using the power of the light source lamp exciter according to the output of the photodetector. Characteristic gas cell type atomic oscillator.